Intel® PXA255 Processor
Developer’s Manual
January, 2004
Order Number: 278693-002
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ii Intel® PXA255 Processor Developer’s Manual
Contents
Contents
1 Introduction...................................................................................................................................1-1
1.1 Intel XScale® Microarchitecture Features.........................................................................1-1
1.2 System Integration Features..............................................................................................1-1
1.2.1 Memory Controller ................................................................................................1-2
1.2.2 Clocks and Power Controllers...............................................................................1-2
1.2.3 Universal Serial Bus (USB) Client.........................................................................1-2
1.2.4 DMA Controller (DMAC) .......................................................................................1-3
1.2.5 LCD Controller ......................................................................................................1-3
1.2.6 AC97 Controller ....................................................................................................1-3
1.2.7 Inter-IC Sound (I2S) Controller .............................................................................1-3
1.2.8 Multimedia Card (MMC) Controller .......................................................................1-3
1.2.9 Fast Infrared (FIR) Communication Port...............................................................1-3
1.2.10 Synchronous Serial Protocol Controller (SSPC)...................................................1-4
1.2.11 Inter-Integrated Circuit (I2C) Bus Interface Unit....................................................1-4
1.2.12 GPIO.....................................................................................................................1-4
1.2.13 UARTs ..................................................................................................................1-4
1.2.14 Real-Time Clock (RTC).........................................................................................1-5
1.2.15 OS Timers.............................................................................................................1-5
1.2.16 Pulse-Width Modulator (PWM) .............................................................................1-5
1.2.17 Interrupt Control....................................................................................................1-5
1.2.18 Network Synchronous Serial Protocol Port...........................................................1-5
2 System Architecture .....................................................................................................................2-1
2.1 Overview............................................................................................................................2-1
2.2 Intel XScale® Microarchitecture Implementation Options.................................................2-2
2.2.1 Coprocessor 7 Register 4 - PSFS Bit ...................................................................2-2
2.2.2 Coprocessor 14 Registers 0-3 - Performance Monitoring.....................................2-3
2.2.3 Coprocessor 14 Register 6 and 7- Clock and Power Management......................2-3
2.2.4 Coprocessor 15 Register 0 - ID Register Definition..............................................2-3
2.2.5 Coprocessor 15 Register 1 - P-Bit ........................................................................2-4
2.3 I/O Ordering.......................................................................................................................2-5
2.4 Semaphores ......................................................................................................................2-5
2.5 Interrupts............................................................................................................................2-5
2.6 Reset .................................................................................................................................2-6
2.7 Internal Registers...............................................................................................................2-7
2.8 Selecting Peripherals vs. General Purpose I/O .................................................................2-7
2.9 Power on Reset and Boot Operation .................................................................................2-8
2.10 Power Management...........................................................................................................2-8
2.11 Pin List...............................................................................................................................2-8
2.12 Memory Map....................................................................................................................2-18
2.13 System Architecture Register Summary..........................................................................2-21
3 Clocks and Power Manager .........................................................................................................3-1
3.1 Clock Manager Introduction...............................................................................................3-1
3.2 Power Manager Introduction..............................................................................................3-2
3.3 Clock Manager...................................................................................................................3-2
Intel® PXA255 Processor Developer’s Manual iii
Contents
3.3.1 32.768 kHz Oscillator............................................................................................3-4
3.3.2 3.6864 MHz Oscillator ..........................................................................................3-4
3.3.3 Core Phase Locked Loop .....................................................................................3-4
3.3.4 95.85 MHz Peripheral Phase Locked Loop ..........................................................3-5
3.3.5 147.46 MHz Peripheral Phase Locked Loop ........................................................3-5
3.3.6 Clock Gating .........................................................................................................3-6
3.4 Resets and Power Modes..................................................................................................3-6
3.4.1 Hardware Reset....................................................................................................3-6
3.4.2 Watchdog Reset ...................................................................................................3-7
3.4.3 GPIO Reset ..........................................................................................................3-8
3.4.4 Run Mode .............................................................................................................3-9
3.4.5 Turbo Mode ..........................................................................................................3-9
3.4.6 Idle Mode............................................................................................................3-10
3.4.7 Frequency Change Sequence............................................................................3-11
3.4.8 33-MHz Idle Mode ..............................................................................................3-13
3.4.9 Sleep Mode.........................................................................................................3-15
3.4.10 Power Mode Summary .......................................................................................3-20
3.5 Power Manager Registers ...............................................................................................3-22
3.5.1 Power Manager Control Register (PMCR) .........................................................3-23
3.5.2 Power Manager General Configuration Register (PCFR)...................................3-24
3.5.3 Power Manager Wake-Up Enable Register (PWER)..........................................3-25
3.5.4 Power Manager Rising-Edge Detect Enable Register (PRER) ..........................3-26
3.5.5 Power Manager Falling-Edge Detect Enable Register (PFER) ..........................3-27
3.5.6 Power Manager GPIO Edge Detect Status Register (PEDR).............................3-28
3.5.7 Power Manager Sleep Status Register (PSSR) .................................................3-29
3.5.8 Power Manager Scratch Pad Register (PSPR) ..................................................3-30
3.5.9 Power Manager Fast Sleep Walk-up Configuration Register (PMFW)...............3-31
3.5.10 Power Manager GPIO Sleep State Registers (PGSR0, PGSR1, PGSR2).........3-31
3.5.11 Reset Controller Status Register (RCSR)...........................................................3-33
3.6 Clocks Manager Registers...............................................................................................3-34
3.6.1 Core Clock Configuration Register (CCCR) .......................................................3-34
3.6.2 Clock Enable Register (CKEN)...........................................................................3-36
3.6.3 Oscillator Configuration Register (OSCC) ..........................................................3-38
3.7 Coprocessor 14: Clock and Power Management ............................................................3-38
3.7.1 Core Clock Configuration Register (CCLKCFG).................................................3-39
3.7.2 Power Mode Register (PWRMODE)...................................................................3-40
3.8 External Hardware Considerations ..................................................................................3-40
3.8.1 Power-On-Reset Considerations........................................................................3-40
3.8.2 Power Supply Connectivity.................................................................................3-40
3.8.3 Driving the Crystal Pins from an External Clock Source.....................................3-41
3.8.4 Noise Coupling Between Driven Crystal Pins and a Crystal Oscillator...............3-41
3.9 Clocks and Power Manager Register Summary..............................................................3-41
3.9.1 Clocks Manager Register Locations...................................................................3-41
3.9.2 Power Manager Register Summary....................................................................3-41
4 System Integration Unit ................................................................................................................4-1
4.1 General-Purpose I/O..........................................................................................................4-1
4.1.1 GPIO Operation....................................................................................................4-1
4.1.2 GPIO Alternate Functions.....................................................................................4-2
4.1.3 GPIO Register Definitions.....................................................................................4-6
iv Intel® PXA255 Processor Developer’s Manual
4.2 Interrupt Controller...........................................................................................................4-20
4.2.1 Interrupt Controller Operation .............................................................................4-20
4.2.2 Interrupt Controller Register Definitions..............................................................4-21
4.3 Real-Time Clock (RTC) ...................................................................................................4-28
4.3.1 Real-Time Clock Operation.................................................................................4-28
4.3.2 RTC Register Definitions ....................................................................................4-29
4.3.3 Trim Procedure ...................................................................................................4-32
4.4 Operating System (OS) Timer .........................................................................................4-34
4.4.1 Watchdog Timer Operation.................................................................................4-35
4.4.2 OS Timer Register Definitions ............................................................................4-35
4.5 Pulse Width Modulator.....................................................................................................4-38
4.5.1 Pulse Width Modulator Operation.......................................................................4-38
4.5.2 Register Descriptions..........................................................................................4-40
4.5.3 Pulse Width Modulator Output Wave Example...................................................4-43
4.6 System Integration Unit Register Summary.....................................................................4-44
4.6.1 GPIO Register Locations....................................................................................4-44
4.6.2 Interrupt Controller Register Locations ...............................................................4-45
4.6.3 Real-Time Clock Register Locations...................................................................4-45
4.6.4 OS Timer Register Locations..............................................................................4-45
4.6.5 Pulse Width Modulator Register Locations.........................................................4-46
Contents
5 DMA Controller.............................................................................................................................5-1
5.1 DMA Description................................................................................................................5-1
5.1.1 DMAC Channels...................................................................................................5-2
5.1.2 Signal Descriptions ...............................................................................................5-2
5.1.3 DMA Channel Priority Scheme .............................................................................5-3
5.1.4 DMA Descriptors...................................................................................................5-5
5.1.5 Channel States .....................................................................................................5-8
5.1.6 Read and Write Order...........................................................................................5-9
5.1.7 Byte Transfer Order ..............................................................................................5-9
5.1.8 Trailing Bytes ......................................................................................................5-10
5.2 Transferring Data.............................................................................................................5-11
5.2.1 Servicing Internal Peripherals.............................................................................5-11
5.2.2 Quick Reference for DMA Programming ............................................................5-13
5.2.3 Servicing Companion Chips and External Peripherals .......................................5-14
5.2.4 Memory-to-Memory Moves.................................................................................5-16
5.3 DMAC Registers ..............................................................................................................5-17
5.3.1 DMA Interrupt Register (DINT) ...........................................................................5-17
5.3.2 DMA Channel Control/Status Register (DCSRx)................................................5-17
5.3.3 DMA Request to Channel Map Registers (DRCMRx) ........................................5-20
5.3.4 DMA Descriptor Address Registers (DDADRx) ..................................................5-20
5.3.5 DMA Source Address Registers .........................................................................5-21
5.3.6 DMA Target Address Registers (DTADRx).........................................................5-22
5.3.7 DMA Command Registers (DCMDx)..................................................................5-23
5.4 Examples.........................................................................................................................5-26
5.5 DMA Controller Register Summary .................................................................................5-28
6 Memory Controller........................................................................................................................6-1
6.1 Overview............................................................................................................................6-1
6.2 Functional Description .......................................................................................................6-2
Intel® PXA255 Processor Developer’s Manual v
Contents
6.2.1 SDRAM Interface Overview..................................................................................6-2
6.2.2 Static Memory Interface / Variable Latency I/O Interface .....................................6-3
6.2.3 16-Bit PC Card / Compact Flash Interface ...........................................................6-4
6.3 Memory System Examples ................................................................................................6-4
6.4 Memory Accesses .............................................................................................................6-7
6.4.1 Reads and Writes .................................................................................................6-8
6.4.2 Aborts and Nonexistent Memory ..........................................................................6-8
6.5 Synchronous DRAM Memory Interface .............................................................................6-8
6.5.1 SDRAM MDCNFG Register (MDCNFG................................................................6-8
6.5.2 SDRAM Mode Register Set Configuration Register (MDMRS) ..........................6-12
6.5.3 SDRAM MDREFR Register (MDREFR) .............................................................6-14
6.5.4 Fixed-Delay or Return-Clock Data Latching.......................................................6-17
6.5.5 SDRAM Memory Options ...................................................................................6-18
6.5.6 SDRAM Command Overview.............................................................................6-27
6.5.7 SDRAM Waveforms............................................................................................6-28
6.6 Synchronous Static Memory Interface.............................................................................6-32
6.6.1 Synchronous Static Memory Configuration Register (SXCNFG)........................6-32
6.6.2 Synchronous Static Memory Mode Register Set Configuration
Register (SXMRS) ..............................................................................................6-37
6.6.3 Synchronous Static Memory Timing Diagrams...................................................6-38
6.6.4 Non-SDRAM Timing SXMEM Operation ............................................................6-39
6.7 Asynchronous Static Memory..........................................................................................6-42
6.7.1 Static Memory Interface......................................................................................6-42
6.7.2 Static Memory SA-1111 Compatibility Configuration Register (SA1111CR)......6-44
6.7.3 Asynchronous Static Memory Control Registers (MSCx)...................................6-46
6.7.4 ROM Interface ....................................................................................................6-50
6.7.5 SRAM Interface Overview ..................................................................................6-53
6.7.6 Variable Latency I/O (VLIO) Interface Overview.................................................6-55
6.7.7 FLASH Memory Interface...................................................................................6-58
6.8 16-Bit PC Card/Compact Flash Interface ........................................................................6-60
6.8.1 Expansion Memory Timing Configuration Register ............................................6-60
6.8.2 Expansion Memory Configuration Register (MECR) ..........................................6-63
6.8.3 16-Bit PC Card Overview....................................................................................6-64
6.8.4 External Logic for 16-Bit PC Card Implementation.............................................6-66
6.8.5 Expansion Card Interface Timing Diagrams and Parameters ............................6-69
6.9 Companion Chip Interface...............................................................................................6-70
6.9.1 Alternate Bus Master Mode ................................................................................6-72
6.10 Options and Settings for Boot Memory............................................................................6-74
6.10.1 Alternate Booting ................................................................................................6-74
6.10.2 Boot Time Defaults .............................................................................................6-74
6.10.3 Memory Interface Reset and Initialization...........................................................6-78
6.11 Hardware, Watchdog, or Sleep Reset Operation ............................................................6-79
6.12 GPIO Reset Procedure....................................................................................................6-81
6.13 Memory Controller Register Summary ............................................................................6-81
7 LCD Controller..............................................................................................................................7-1
7.1 Overview............................................................................................................................7-1
7.1.1 Features................................................................................................................7-2
7.1.2 Pin Descriptions....................................................................................................7-4
7.2 LCD Controller Operation ..................................................................................................7-4
vi Intel® PXA255 Processor Developer’s Manual
7.2.1 Enabling the Controller .........................................................................................7-4
7.2.2 Disabling the Controller ........................................................................................7-5
7.2.3 Resetting the Controller........................................................................................7-5
7.3 Detailed Module Descriptions ............................................................................................7-5
7.3.1 Input FIFOs...........................................................................................................7-5
7.3.2 Lookup Palette......................................................................................................7-6
7.3.3 Temporal Modulated Energy Distribution (TMED) Dithering.................................7-6
7.3.4 Output FIFOs ........................................................................................................7-8
7.3.5 LCD Controller Pin Usage ....................................................................................7-8
7.3.6 DMA......................................................................................................................7-9
7.4 LCD External Palette and Frame Buffers ........................................................................7-10
7.4.1 External Palette Buffer........................................................................................7-10
7.4.2 External Frame Buffer.........................................................................................7-11
7.5 Functional Timing ............................................................................................................7-14
7.6 Register Descriptions.......................................................................................................7-17
7.6.1 LCD Controller Control Register 0 (LCCR0).......................................................7-18
7.6.2 LCD Controller Control Register 1 (LCCR1).......................................................7-24
7.6.3 LCD Controller Control Register 2 (LCCR2).......................................................7-26
7.6.4 LCD Controller Control Register 3 (LCCR3).......................................................7-28
7.6.5 LCD Controller DMA ...........................................................................................7-32
7.6.6 LCD DMA Frame Branch Registers (FBRx) .......................................................7-37
7.6.7 LCD Controller Status Register (LCSR)..............................................................7-38
7.6.8 LCD Controller Interrupt ID Register (LIIDR) ......................................................7-41
7.6.9 TMED RGB Seed Register (TRGBR) .................................................................7-42
7.6.10 TMED Control Register (TCR)............................................................................7-43
7.7 LCD Controller Register Summary ..................................................................................7-44
Contents
8 Synchronous Serial Port Controller ..............................................................................................8-1
8.1 Overview............................................................................................................................8-1
8.2 Signal Description..............................................................................................................8-1
8.2.1 External Interface to Synchronous Serial Peripherals ..........................................8-1
8.3 Functional Description .......................................................................................................8-2
8.3.1 Data Transfer........................................................................................................8-2
8.4 Data Formats.....................................................................................................................8-2
8.4.1 Serial Data Formats for Transfer to/from Peripherals...........................................8-2
8.4.2 Parallel Data Formats for FIFO Storage...............................................................8-6
8.5 FIFO Operation and Data Transfers..................................................................................8-7
8.5.1 Using Programmed I/O Data Transfers ................................................................8-7
8.5.2 Using DMA Data Transfers...................................................................................8-7
8.6 Baud-Rate Generation.......................................................................................................8-7
8.7 SSP Serial Port Registers..................................................................................................8-8
8.7.1 SSP Control Register 0 (SSCR0) .........................................................................8-8
8.7.2 SSP Control Register 1 (SSCR1) .......................................................................8-11
8.7.3 SSP Data Register (SSDR) ................................................................................8-15
8.7.4 SSP Status Register (SSSR)..............................................................................8-16
8.8 SSP Controller Register Summary ..................................................................................8-19
9I2C Bus Interface Unit...................................................................................................................9-1
9.1 Overview............................................................................................................................9-1
9.2 Signal Description..............................................................................................................9-1
Intel® PXA255 Processor Developer’s Manual vii
Contents
9.3 Functional Description .......................................................................................................9-1
9.3.1 Operational Blocks................................................................................................9-3
9.3.2 I2C Bus Interface Modes .....................................................................................9-3
9.3.3 Start and Stop Bus States ....................................................................................9-4
9.4 I2C Bus Operation .............................................................................................................9-7
9.4.1 Serial Clock Line (SCL) Generation......................................................................9-7
9.4.2 Data and Addressing Management ......................................................................9-7
9.4.3 I2C Acknowledge..................................................................................................9-8
9.4.4 Polling...................................................................................................................9-9
9.4.5 Arbitration .............................................................................................................9-9
9.4.6 Master Operations..............................................................................................9-12
9.4.7 Slave Operations ................................................................................................9-14
9.4.8 General Call Address.......................................................................................... 9-16
9.5 Slave Mode Programming Examples ..............................................................................9-18
9.5.1 Initialize Unit .......................................................................................................9-18
9.5.2 Write n Bytes as a Slave.....................................................................................9-18
9.5.3 Read n Bytes as a Slave ....................................................................................9-18
9.6 Master Programming Examples ......................................................................................9-19
9.6.1 Initialize Unit .......................................................................................................9-19
9.6.2 Write 1 Byte as a Master ....................................................................................9-19
9.6.3 Read 1 Byte as a Master ....................................................................................9-20
9.6.4 Write 2 Bytes and Repeated Start Read 1 Byte as a Master..............................9-20
9.6.5 Read 2 Bytes as a Master - Send STOP Using the Abort ..................................9-21
9.7 Glitch Suppression Logic.................................................................................................9-21
9.8 Reset Conditions .............................................................................................................9-21
9.9 Register Definitions..........................................................................................................9-22
9.9.1 I2C Bus Monitor Register (IBMR).......................................................................9-22
9.9.2 I2C Data Buffer Register (IDBR).........................................................................9-22
9.9.3 I2C Control Register (ICR)..................................................................................9-23
9.9.4 I2C Status Register (ISR) ...................................................................................9-25
9.9.5 I2C Slave Address Register (ISAR)....................................................................9-27
10 UARTs........................................................................................................................................10-1
10.1 Feature List......................................................................................................................10-1
10.2 Overview..........................................................................................................................10-2
10.2.1 Full Function UART ............................................................................................10-2
10.2.2 Bluetooth UART..................................................................................................10-2
10.2.3 Standard UART ..................................................................................................10-2
10.2.4 Compatibility with 16550.....................................................................................10-2
10.3 Signal Descriptions..........................................................................................................10-3
10.4 UART Operational Description ........................................................................................10-4
10.4.1 Reset ..................................................................................................................10-5
10.4.2 Internal Register Descriptions.............................................................................10-5
10.4.3 FIFO Interrupt Mode Operation ........................................................................10-21
10.4.4 FIFO Polled Mode Operation............................................................................10-22
10.4.5 DMA Requests..................................................................................................10-22
10.4.6 Slow Infrared Asynchronous Interface..............................................................10-23
10.5 UART Register Summary ..............................................................................................10-26
10.5.1 UART Register Differences ..............................................................................10-28
viii Intel® PXA255 Processor Developer’s Manual
Contents
11 Fast Infrared Communication Port..............................................................................................11-1
11.1 Signal Description............................................................................................................11-1
11.2 FICP Operation................................................................................................................11-1
11.2.1 4PPM Modulation ...............................................................................................11-2
11.2.2 Frame Format.....................................................................................................11-3
11.2.3 Address Field......................................................................................................11-3
11.2.4 Control Field .......................................................................................................11-3
11.2.5 Data Field ...........................................................................................................11-3
11.2.6 CRC Field ...........................................................................................................11-4
11.2.7 Baud Rate Generation........................................................................................11-4
11.2.8 Receive Operation ..............................................................................................11-4
11.2.9 Transmit Operation .............................................................................................11-5
11.2.10 Transmit and Receive FIFOs..............................................................................11-6
11.2.11 Trailing or Error Bytes in the Receive FIFO........................................................11-7
11.3 FICP Register Definitions ................................................................................................11-7
11.3.1 FICP Control Register 0 (ICCR0)........................................................................11-8
11.3.2 FICP Control Register 1 (ICCR1)......................................................................11-10
11.3.3 FICP Control Register 2 (ICCR2)......................................................................11-11
11.3.4 FICP Data Register (ICDR)...............................................................................11-12
11.3.5 FICP Status Register 0 (ICSR0) .......................................................................11-13
11.3.6 FICP Status Register 1 (ICSR1) .......................................................................11-15
11.4 FICP Register Summary................................................................................................11-16
12 USB Device Controller................................................................................................................12-1
12.1 USB Overview .................................................................................................................12-1
12.2 Device Configuration .......................................................................................................12-2
12.3 USB Protocol ...................................................................................................................12-2
12.3.1 Signalling Levels.................................................................................................12-3
12.3.2 Bit Encoding........................................................................................................12-3
12.3.3 Field Formats......................................................................................................12-4
12.3.4 Packet Formats...................................................................................................12-5
12.3.5 Transaction Formats...........................................................................................12-6
12.3.6 UDC Device Requests........................................................................................12-8
12.3.7 Configuration ......................................................................................................12-9
12.4 UDC Hardware Connection ...........................................................................................12-10
12.4.1 Self-Powered Device ........................................................................................12-10
12.4.2 Bus-Powered Devices ......................................................................................12-12
12.5 UDC Operation ..............................................................................................................12-12
12.5.1 Case 1: EP0 Control Read ...............................................................................12-12
12.5.2 Case 2: EP0 Control Read with a Premature Status Stage..............................12-13
12.5.3 Case 3: EP0 Control Write With or Without a Premature Status Stage............12-14
12.5.4 Case 4: EP0 No Data Command......................................................................12-15
12.5.5 Case 5: EP1 Data Transmit (BULK-IN).............................................................12-15
12.5.6 Case 6: EP2 Data Receive (BULK-OUT)..........................................................12-16
12.5.7 Case 7: EP3 Data Transmit (ISOCHRONOUS-IN)...........................................12-17
12.5.8 Case 8: EP4 Data Receive (ISOCHRONOUS-OUT)........................................12-18
12.5.9 Case 9: EP5 Data Transmit (INTERRUPT-IN) .................................................12-20
12.5.10 Case 10: RESET Interrupt ................................................................................12-20
12.5.11 Case 11: SUSPEND Interrupt...........................................................................12-21
12.5.12 Case 12: RESUME Interrupt.............................................................................12-21
Intel® PXA255 Processor Developer’s Manual ix
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12.6 UDC Register Definitions...............................................................................................12-21
12.6.1 UDC Control Register (UDCCR).......................................................................12-22
12.6.2 UDC Control Function Register (UDCCFR)......................................................12-24
12.6.3 UDC Endpoint 0 Control/Status Register (UDCCS0) .......................................12-25
12.6.4 UDC Endpoint x Control/Status Register (UDCCS1/6/11)................................12-27
12.6.5 UDC Endpoint x Control/Status Register (UDCCS2/7/12)................................12-29
12.6.6 UDC Endpoint x Control/Status Register (UDCCS3/8/13)................................12-31
12.6.7 UDC Endpoint x Control/Status Register (UDCCS4/9/14)................................12-32
12.6.8 UDC Endpoint x Control/Status Register (UDCCS5/10/15)..............................12-34
12.6.9 UDC Interrupt Control Register 0 (UICR0) .......................................................12-36
12.6.10 UDC Interrupt Control Register 1 (UICR1) .......................................................12-38
12.6.11 UDC Status/Interrupt Register 0 (USIR0).........................................................12-39
12.6.12 UDC Status/Interrupt Register 1 (USIR1).........................................................12-41
12.6.13 UDC Frame Number High Register (UFNHR) ..................................................12-42
12.6.14 UDC Frame Number Low Register (UFNLR) ...................................................12-44
12.6.15 UDC Byte Count Register x (UBCR2/4/7/9/12/14) ...........................................12-44
12.6.16 UDC Endpoint 0 Data Register (UDDR0).........................................................12-45
12.6.17 UDC Endpoint x Data Register (UDDR1/6/11) .................................................12-46
12.6.18 UDC Endpoint x Data Register (UDDR2/7/12) .................................................12-46
12.6.19 UDC Endpoint x Data Register (UDDR3/8/13) .................................................12-47
12.6.20 UDC Endpoint x Data Register (UDDR4/9/14) .................................................12-47
12.6.21 UDC Endpoint x Data Register (UDDR5/10/15) ...............................................12-48
12.7 USB Device Controller Register Summary....................................................................12-48
13 AC’97 Controller Unit..................................................................................................................13-1
13.1 Overview..........................................................................................................................13-1
13.2 Feature List......................................................................................................................13-1
13.3 Signal Description............................................................................................................13-2
13.3.1 Signal Configuration Steps .................................................................................13-2
13.3.2 Example AC-link .................................................................................................13-2
13.4 AC-link Digital Serial Interface Protocol...........................................................................13-3
13.4.1 AC-link Audio Output Frame (SDATA_OUT)......................................................13-4
13.4.2 AC-link Audio Input Frame (SDATA_IN).............................................................13-8
13.5 AC-link Low Power Mode ..............................................................................................13-12
13.5.1 Powering Down the AC-link..............................................................................13-12
13.5.2 Waking up the AC-link ......................................................................................13-13
13.6 ACUNIT Operation.........................................................................................................13-14
13.6.1 Initialization.......................................................................................................13-15
13.6.2 Trailing bytes ....................................................................................................13-17
13.6.3 Operational Flow for Accessing CODEC Registers..........................................13-17
13.7 Clocks and Sampling Frequencies ................................................................................13-17
13.8 Functional Description ...................................................................................................13-18
13.8.1 FIFOs................................................................................................................13-18
13.8.2 Interrupts...........................................................................................................13-19
13.8.3 Registers...........................................................................................................13-19
13.9 AC’97 Register Summary ..............................................................................................13-35
14 Inter-Integrated-Circuit Sound (I2S) Controller...........................................................................14-1
14.1 Overview..........................................................................................................................14-1
14.2 Signal Descriptions..........................................................................................................14-2
x Intel® PXA255 Processor Developer’s Manual
14.3 Controller Operation ........................................................................................................14-3
14.3.1 Initialization .........................................................................................................14-3
14.3.2 Disabling and Enabling Audio Replay.................................................................14-4
14.3.3 Disabling and Enabling Audio Record ................................................................14-4
14.3.4 Transmit FIFO Errors..........................................................................................14-5
14.3.5 Receive FIFO Errors...........................................................................................14-5
14.3.6 Trailing Bytes ......................................................................................................14-5
14.4 Serial Audio Clocks and Sampling Frequencies..............................................................14-5
14.5 Data Formats...................................................................................................................14-6
14.5.1 FIFO and Memory Format ..................................................................................14-6
14.5.2 I2S and MSB-Justified Serial Audio Formats......................................................14-6
14.6 Registers..........................................................................................................................14-8
14.6.1 Serial Audio Controller Global Control Register (SACR0) ..................................14-8
14.6.2 Serial Audio Controller I2S/MSB-Justified Control Register (SACR1)..............14-10
14.6.3 Serial Audio Controller I2S/MSB-Justified Status Register (SASR0)................14-11
14.6.4 Serial Audio Clock Divider Register (SADIV)....................................................14-12
14.6.5 Serial Audio Interrupt Clear Register (SAICR)..................................................14-13
14.6.6 Serial Audio Interrupt Mask Register (SAIMR) .................................................14-14
14.6.7 Serial Audio Data Register (SADR) ..................................................................14-14
14.7 Interrupts........................................................................................................................14-15
2
14.8 I
S Controller Register Summary ..................................................................................14-15
Contents
15 MultiMediaCard Controller..........................................................................................................15-1
15.1 Overview..........................................................................................................................15-1
15.2 MMC Controller Functional Description...........................................................................15-4
15.2.1 Signal Description...............................................................................................15-6
15.2.2 MMC Controller Reset ........................................................................................15-6
15.2.3 Card Initialization Sequence ...............................................................................15-6
15.2.4 MMC and SPI Modes..........................................................................................15-6
15.2.5 Error Detection....................................................................................................15-8
15.2.6 Interrupts.............................................................................................................15-8
15.2.7 Clock Control ......................................................................................................15-9
15.2.8 Data FIFOs .......................................................................................................15-10
15.3 Card Communication Protocol.......................................................................................15-12
15.3.1 Basic, No Data, Command and Response Sequence......................................15-13
15.3.2 Data Transfer....................................................................................................15-13
15.3.3 Busy Sequence.................................................................................................15-16
15.3.4 SPI Functionality...............................................................................................15-17
15.4 MultiMediaCard Controller Operation ............................................................................15-17
15.4.1 Start and Stop Clock.........................................................................................15-17
15.4.2 Initialize.............................................................................................................15-17
15.4.3 Enabling SPI Mode ...........................................................................................15-17
15.4.4 No Data Command and Response Sequence..................................................15-18
15.4.5 Erase ................................................................................................................15-18
15.4.6 Single Data Block Write....................................................................................15-18
15.4.7 Single Block Read ............................................................................................15-19
15.4.8 Multiple Block Write ..........................................................................................15-20
15.4.9 Multiple Block Read ..........................................................................................15-20
15.4.10 Stream Write.....................................................................................................15-21
15.4.11 Stream Read.....................................................................................................15-21
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Contents
15.5 MMC Controller Registers ............................................................................................. 15-22
15.5.1 MMC_STRPCL Register...................................................................................15-22
15.5.2 MMC_Status Register (MMC_STAT) ...............................................................15-23
15.5.3 MMC_CLKRT Register (MMC_CLKRT) ...........................................................15-24
15.5.4 MMC_SPI Register (MMC_SPI) .......................................................................15-25
15.5.5 MMC_CMDAT Register (MMC_CMDAT) .........................................................15-26
15.5.6 MMC_RESTO Register (MMC_RESTO)..........................................................15-27
15.5.7 MMC_RDTO Register (MMC_RDTO) ..............................................................15-28
15.5.8 MMC_BLKLEN Register (MMC_BLKLEN) .......................................................15-29
15.5.9 MMC_NOB Register (MMC_NOB) ...................................................................15-29
15.5.10 MMC_PRTBUF Register (MMC_PRTBUF)......................................................15-30
15.5.11 MMC_I_MASK Register (MMC_I_MASK) ........................................................15-30
15.5.12 MMC_I_REG Register (MMC_I_REG) .............................................................15-31
15.5.13 MMC_CMD Register (MMC_CMD) ..................................................................15-33
15.5.14 MMC_ARGH Register (MMC_ARGH)..............................................................15-35
15.5.15 MMC_ARGL Register (MMC_ARGL) ...............................................................15-35
15.5.16 MMC_RES FIFO...............................................................................................15-36
15.5.17 MMC_RXFIFO FIFO.........................................................................................15-36
15.5.18 MMC_TXFIFO FIFO.........................................................................................15-37
15.6 MultiMediaCard Controller Register Summary ..............................................................15-37
16 Network SSP Serial Port ............................................................................................................16-1
16.1 Overview..........................................................................................................................16-1
16.2 Features...........................................................................................................................16-1
16.3 Signal Description............................................................................................................16-2
16.4 Operation.........................................................................................................................16-2
16.4.1 Processor and DMA FIFO Access......................................................................16-2
16.4.2 Trailing Bytes in the Receive FIFO.....................................................................16-3
16.4.3 Data Formats......................................................................................................16-3
16.4.4 Hi-Z on SSPTXD...............................................................................................16-13
16.4.5 FIFO Operation.................................................................................................16-17
16.4.6 Baud-Rate Generation......................................................................................16-17
16.5 Register Descriptions.....................................................................................................16-18
16.5.1 SSP Control Register 0 (SSCR0) ..................................................................... 16-18
16.5.2 SSP Control Register 1 (SSCR1) ..................................................................... 16-20
16.5.3 SSP Programmable Serial Protocol Register (SSPSP)....................................16-22
16.5.4 SSP Time Out Register (SSTO) .......................................................................16-24
16.5.5 SSP Interrupt Test Register (SSITR)................................................................16-24
16.5.6 SSP Status Register (SSSR)............................................................................16-25
16.5.7 SSP Data Register (SSDR) ..............................................................................16-28
16.6 Network SSP Serial Port Register Summary.................................................................16-29
17 Hardware UART.........................................................................................................................17-1
17.1 Overview..........................................................................................................................17-1
17.2 Features...........................................................................................................................17-1
17.3 Signal Descriptions..........................................................................................................17-3
17.4 Operation.........................................................................................................................17-3
17.4.1 Reset ..................................................................................................................17-4
17.4.2 FIFO Operation...................................................................................................17-4
17.4.3 Autoflow Control .................................................................................................17-7
xii Intel® PXA255 Processor Developer’s Manual
17.4.4 Auto-Baud-Rate Detection..................................................................................17-7
17.4.5 Slow Infrared Asynchronous Interface................................................................17-8
17.5 Register Descriptions.....................................................................................................17-10
17.5.1 Receive Buffer Register (RBR).........................................................................17-10
17.5.2 Transmit Holding Register (THR)......................................................................17-10
17.5.3 Divisor Latch Registers (DLL and DLH)............................................................17-10
17.5.4 Interrupt Enable Register (IER) ........................................................................17-11
17.5.5 Interrupt Identification Register (IIR).................................................................17-13
17.5.6 FIFO Control Register (FCR)............................................................................17-15
17.5.7 Receive FIFO Occupancy Register (FOR) .......................................................17-16
17.5.8 Auto-Baud Control Register (ABR) ...................................................................17-17
17.5.9 Auto-Baud Count Register (ACR).....................................................................17-17
17.5.10 Line Control Register (LCR)..............................................................................17-18
17.5.11 Line Status Register (LSR) ...............................................................................17-19
17.5.12 Modem Control Register (MCR) .......................................................................17-21
17.5.13 Modem Status Register (MSR) .........................................................................17-23
17.5.14 Scratchpad Register (SCR) ..............................................................................17-24
17.5.15 Infrared Selection Register (ISR)......................................................................17-24
17.6 Hardware UART Register Summary..............................................................................17-25
Contents
Figures
2-1 Block Diagram ...........................................................................................................................2-2
2-2 Memory Map (Part One) — From 0x8000_0000 to 0xFFFF FFFF ..........................................2-19
2-3 Memory Map (Part Two) — From 0x0000_0000 to 0x7FFF FFFF ..........................................2-20
3-1 Clocks Manager Block Diagram ................................................................................................3-3
4-1 General-Purpose I/O Block Diagram .........................................................................................4-2
4-2 Interrupt Controller Block Diagram ..........................................................................................4-21
4-3 PWMn Block Diagram..............................................................................................................4-39
4-4 Basic Pulse Width Waveform ..................................................................................................4-43
5-1 DMAC Block Diagram................................................................................................................5-1
5-2 DREQ timing requirements........................................................................................................5-3
5-3 No-Descriptor Fetch Mode Channel State.................................................................................5-6
5-4 Descriptor Fetch Mode Channel State.......................................................................................5-8
5-5 Little Endian Transfers.............................................................................................................5-10
6-1 General Memory Interface Configuration...................................................................................6-2
6-2 SDRAM Memory System Example............................................................................................6-5
6-3 Static Memory System Example................................................................................................6-6
6-4 External to Internal Address Mapping Options ........................................................................6-19
6-5 Basic SDRAM Timing Parameters...........................................................................................6-29
6-6 SDRAM_Read_diffbank_diffrow..............................................................................................6-29
6-7 SDRAM_read_samebank_diffrow ...........................................................................................6-30
6-8 SDRAM_read_samebank_samerow .......................................................................................6-30
6-9 SDRAM_write ..........................................................................................................................6-31
6-10 SDRAM 4-Beat Read/ 4-Beat Write To Different Partitions.....................................................6-31
6-11 SDRAM 4-Beat Write / 4-Write Same Bank, Same Row .........................................................6-32
6-12 SMROM Read Timing Diagram Half-Memory Clock Frequency .............................................6-39
6-13 Burst-of-Eight Synchronous Flash Timing Diagram (non-divide-by-2 mode) ..........................6-41
6-14 Flash Memory Reset Using State Machine .............................................................................6-42
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Contents
6-15 Flash Memory Reset Logic if Watchdog Reset is Not Necessary ...........................................6-42
6-16 MSC0/1/2.................................................................................................................................6-46
6-17 32-Bit Burst-of-Eight ROM or Flash Read Timing Diagram (MSC0[RDF] = 4,
MSC0[RDN] = 1, MSC0[RRR] = 1)..........................................................................................6-51
6-18 Eight-Beat Burst Read from 16-Bit Burst-of-Four ROM or Flash
(MSC0[RDF] = 4, MSC0[RDN] = 1, MSC0[RRR] = 0).............................................................6-52
6-19 32-Bit Non-burst ROM, SRAM, or Flash Read Timing Diagram - Four Data
Beats (MSC0[RDF] = 4, MSC0[RRR] = 1)...............................................................................6-53
6-20 32-Bit SRAM Write Timing Diagram (4-beat Burst (MSC0[RDN] = 2,
MSC0[RRR] = 1)......................................................................................................................6-54
6-21 32-Bit Variable Latency I/O Read Timing (Burst-of-Four, One Wait Cycle Per
Beat) (MSC0[RDF] = 2, MSC0[RDN] = 2, MSC0[RRR] = 1) ...................................................6-56
6-22 32-Bit Variable Latency I/O Write Timing (Burst-of-Four, Variable Wait Cycles
Per Beat) .................................................................................................................................6-57
6-23 Asynchronous 32-Bit Flash Write Timing Diagram (2 Writes) .................................................6-59
6-24 MCMEM1.................................................................................................................................6-60
6-25 MCATT1 ..................................................................................................................................6-60
6-26 16-Bit PC Card Memory Map ..................................................................................................6-64
6-27 Expansion Card External Logic for a One-Socket Configuration.............................................6-67
6-28 Expansion Card External Logic for a Two-Socket Configuration.............................................6-68
6-29 16-Bit PC Card Memory or I/O 16-Bit (Half-word) Access.......................................................6-69
6-30 16-Bit PC Card I/O 16-Bit Access to 8-Bit Device ...................................................................6-70
6-31 Alternate Bus Master Mode.....................................................................................................6-71
6-32 Variable Latency IO.................................................................................................................6-71
6-33 Asynchronous Boot Time Configurations and Register Defaults.............................................6-76
6-34 SMROM Boot Time Configurations and Register Defaults......................................................6-77
6-35 SMROM Boot Time Configurations and Register Defaults......................................................6-78
7-1 LCD Controller Block Diagram ..................................................................................................7-3
7-2 Temporal Dithering Concept - Single Color...............................................................................7-6
7-3 Compare Range for TMED........................................................................................................7-7
7-4 TMED Block Diagram ...............................................................................................................7-8
7-5 Palette Buffer Format ..............................................................................................................7-11
7-6 1 Bit Per Pixel Data Memory Organization.............................................................................. 7-11
7-7 2 Bits Per Pixel Data Memory Organization ............................................................................7-12
7-8 4 Bits Per Pixel Data Memory Organization ............................................................................7-12
7-9 8 Bits Per Pixel Data Memory Organization ............................................................................7-12
7-10 16 Bits Per Pixel Data Memory Organization - Passive Mode ................................................7-13
7-11 16 Bits Per Pixel Data Memory Organization - Active Mode ...................................................7-13
7-12 Passive Mode Start-of-Frame Timing......................................................................................7-15
7-13 Passive Mode End-of-Frame Timing.......................................................................................7-15
7-14 Passive Mode Pixel Clock and Data Pin Timing......................................................................7-16
7-15 Active Mode Timing .................................................................................................................7-16
7-16 Active Mode Pixel Clock and Data Pin Timing ........................................................................7-17
7-17 Frame Buffer/Palette Output to LCD Data Pins in Active Mode ..............................................7-20
7-18 LCD Data-Pin Pixel Ordering...................................................................................................7-22
8-1 Texas Instruments’ Synchronous Serial Frame* Format...........................................................8-4
8-2 Motorola SPI* Frame Format.....................................................................................................8-5
8-3 National Microwire* Frame Format............................................................................................8-6
8-4 Motorola SPI* Frame Formats for SPO and SPH Programming.............................................8-13
9-1 I
2
C Bus Configuration Example................................................................................................9-2
9-2 Start and Stop Conditions..........................................................................................................9-5
xiv Intel® PXA255 Processor Developer’s Manual
Contents
9-3 START and STOP Conditions ...................................................................................................9-6
9-4 Data Format of First Byte in Master Transaction.......................................................................9-8
9-5 Acknowledge on the I2C Bus.....................................................................................................9-9
9-6 Clock Synchronization During the Arbitration Procedure.........................................................9-10
9-7 Arbitration Procedure of Two Masters .....................................................................................9-11
9-8 Master-Receiver Read from Slave-Transmitter .......................................................................9-14
9-9 Master-Receiver Read from Slave-Transmitter / Repeated Start / Master-
Transmitter Write to Slave-Receiver........................................................................................9-14
9-10 A Complete Data Transfer .......................................................................................................9-14
9-11 Master-Transmitter Write to Slave-Receiver............................................................................9-16
9-12 Master-Receiver Read to Slave-Transmitter ...........................................................................9-16
9-13 Master-Receiver Read to Slave-Transmitter, Repeated START, Master-
Transmitter Write to Slave-Receiver........................................................................................9-16
9-14 General Call Address...............................................................................................................9-17
10-1 Example UART Data Frame ....................................................................................................10-4
10-2 Example NRZ Bit Encoding – (0b0100 1011 ...........................................................................10-5
10-3 IR Transmit and Receive Example ........................................................................................10-25
10-4 XMODE Example...................................................................................................................10-25
11-1 4PPM Modulation Encodings...................................................................................................11-2
11-2 4PPM Modulation Example .....................................................................................................11-2
11-3 Frame Format for IrDA Transmission (4.0 Mbps)....................................................................11-3
12-1 NRZI Bit Encoding Example ....................................................................................................12-4
12-2 Self-Powered Device .............................................................................................................12-11
13-1 Data Transfer Through the AC-link..........................................................................................13-3
13-2 AC’97 Standard Bidirectional Audio Frame .............................................................................13-4
13-3 AC-link Audio Output Frame....................................................................................................13-5
13-4 Start of Audio Output Frame....................................................................................................13-5
13-5 AC’97 Input Frame...................................................................................................................13-9
13-6 Start of an Audio Input Frame..................................................................................................13-9
13-7 AC-link Powerdown Timing....................................................................................................13-12
13-8 SDATA_IN Wake Up Signaling..............................................................................................13-13
13-9 PCM Transmit and Receive Operation ..................................................................................13-27
13-10 Mic-in Receive-Only Operation..............................................................................................13-29
13-11 Modem Transmit and Receive Operation ..............................................................................13-32
14-1 I2S Data Formats (16 bits).......................................................................................................14-7
14-2 MSB-Justified Data Formats (16 bits .......................................................................................14-7
14-3 Transmit and Receive FIFO Accesses Through the SADR...................................................14-15
15-1 MMC System Interaction .........................................................................................................15-1
15-2 MMC Mode Operation Without Data Token.............................................................................15-3
15-3 MMC Mode Operation With Data Token..................................................................................15-3
15-4 SPI Mode Operation Without Data Token ...............................................................................15-4
15-5 SPI Mode Read Operation.......................................................................................................15-4
15-6 SPI Mode Write Operation.......................................................................................................15-4
16-1 Texas Instruments Synchronous Serial Frame* Protocol (multiple transfers) .........................16-5
16-2 Texas Instruments Synchronous Serial Frame* Protocol (single transfers) ............................16-6
16-3 Motorola SPI* Frame Protocol (multiple transfers) ..................................................................16-7
16-4 Motorola SPI* Frame Protocol (single transfers) .....................................................................16-7
16-5 Motorola SPI* Frame Protocols for SPO and SPH Programming (multiple transfers).............16-8
16-6 Motorola SPI* Frame Protocols for SPO and SPH Programming (single transfers)................16-9
16-7 National Semiconductor Microwire* Frame Protocol (multiple transfers) ..............................16-10
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Contents
16-8 National Semiconductor Microwire* Frame Protocol (single transfers) .................................16-10
16-9 Programmable Serial Protocol (multiple transfers)................................................................16-11
16-10 Programmable Serial Protocol (single transfers)...................................................................16-12
16-11 TI SSP with SSCR[TTE]=1 and SSCR[TTELP]=0.................................................................16-13
16-12 TI SSP with SSCR[TTE]=1 and SSCR[TTELP]=1.................................................................16-14
16-13 Motorola SPI with SSCR[TTE]=1...........................................................................................16-14
16-14 National Semiconductor Microwire with SSCR1[TTE]=1.......................................................16-15
16-15 PSP mode with SSCR1[TTE]=1 and SSCR1[TTELP]=0 (slave to frame).............................16-15
16-16 PSP mode with SSCR1[TTE]=1 and SSCR1[TTELP]=0 (master to frame) ..........................16-16
16-17 PSP mode with SSCR1[TTE]=1 and SSCR1[TTELP]=1 (must be slave to frame)...............16-16
17-1 Example UART Data Frame....................................................................................................17-3
17-2 Example NRZ Bit Encoding – (0b0100 1011...........................................................................17-4
17-3 IR Transmit and Receive Example..........................................................................................17-9
17-4 XMODE Example. ...................................................................................................................17-9
Tables
2-1CPU Core Fault Register Bit Definitions...............................................................................2-3
2-2 ID Bit Definitions........................................................................................................................2-4
2-3 PXA255 Processor ID Values....................................................................................................2-4
2-4 Effect of Each Type of Reset on Internal Register State...........................................................2-6
2-5 Processor Pin Types .................................................................................................................2-8
2-6 Pin & Signal Descriptions for the PXA255 Processor................................................................2-9
2-7 Pin Description Notes..............................................................................................................2-17
2-8 System Architecture Register Address Summary ...................................................................2-21
3-1 Core PLL Output Frequencies for 3.6864 MHz Crystal.............................................................3-5
3-2 95.85 MHz Peripheral PLL Output Frequencies for 3.6864 MHz Crystal ..................................3-5
3-3 147.46 MHz Peripheral PLL Output Frequencies for 3.6864 MHz Crystal................................3-6
3-4 Power Mode Entry Sequence Table.......................................................................................3-20
3-5 Power Mode Exit Sequence Table .........................................................................................3-20
3-6 Power and Clock Supply Sources and States During Power Modes .....................................3-22
3-7 PMCR Bit Definitions ...............................................................................................................3-23
3-8 PCFR Bit Definitions................................................................................................................3-24
3-9 PWER Bit Definitions...............................................................................................................3-25
3-10 PRER Bit Definitions................................................................................................................3-26
3-11 PFER Bit Definitions................................................................................................................3-27
3-12 PEDR Bit Definitions................................................................................................................3-28
3-13 PSSR Bit Definitions................................................................................................................3-29
3-14 PSPR Bit Definitions................................................................................................................3-30
3-15 PMFW Register Bitmap and Bit Definitions.............................................................................3-31
3-16 PGSR0 Bit Definitions .............................................................................................................3-32
3-17 PGSR1 Bit Definitions .............................................................................................................3-32
3-18 PGSR2 Bit Definitions .............................................................................................................3-33
3-19 RCSR Bit Definitions ...............................................................................................................3-34
3-20 CCCR Bit Definitions ...............................................................................................................3-35
3-21 CKEN Bit Definitions................................................................................................................3-36
3-22 OSCC Bit Definitions ...............................................................................................................3-38
3-23 Coprocessor 14 Clock and Power Management Summary.....................................................3-39
3-24 CCLKCFG Bit Definitions ........................................................................................................3-39
3-25 PWRMODE Bit Definitions ......................................................................................................3-40
xvi Intel® PXA255 Processor Developer’s Manual
Contents
3-26 Clocks Manager Register Summary........................................................................................3-41
3-27 Power Manager Register Summary.........................................................................................3-42
4-1 GPIO Alternate Functions.......................................................................................................... 4-3
4-2 GPIO Register Definitions..........................................................................................................4-6
4-3 GPLR0 Bit Definitions................................................................................................................4-7
4-4 GPLR1 Bit Definitions................................................................................................................4-8
4-5 GPLR2 Bit Definitions................................................................................................................4-8
4-6 GPDR0 Bit Definitions ...............................................................................................................4-9
4-7 GPDR1 Bit Definitions ...............................................................................................................4-9
4-8 GPDR2 Bit Definitions ...............................................................................................................4-9
4-9 GPSR0 Bit Definitions..............................................................................................................4-10
4-10 GPSR1 Bit Definitions..............................................................................................................4-10
4-11 GPSR2 Bit Definitions..............................................................................................................4-11
4-12 GPCR0 Bit Definitions .............................................................................................................4-11
4-13 GPCR1 Bit Definitions .............................................................................................................4-11
4-14 GPCR2 Bit Definitions .............................................................................................................4-12
4-15 GRER0 Bit Definitions .............................................................................................................4-13
4-16 GRER1 Bit Definitions .............................................................................................................4-13
4-17 GRER2 Bit Definitions .............................................................................................................4-13
4-18 GFER0 Bit Definitions..............................................................................................................4-14
4-19 GFER1 Bit Definitions..............................................................................................................4-14
4-20 GFER2 Bit Definitions..............................................................................................................4-14
4-21 GEDR0 Bit Definitions .............................................................................................................4-15
4-22 GEDR1 Bit Definitions .............................................................................................................4-15
4-23 GEDR2 Bit Definitions .............................................................................................................4-16
4-24 GAFR0_L Bit Definitions..........................................................................................................4-17
4-25 GAFR0_U Bit Definitions .........................................................................................................4-17
4-26 GAFR1_L Bit Definitions..........................................................................................................4-18
4-27 GAFR1_U Bit Definitions .........................................................................................................4-18
4-28 GAFR2_L Bit Definitions..........................................................................................................4-19
4-29 GAFR2_U Bit Definitions .........................................................................................................4-19
4-30 ICMR Bit Definitions.................................................................................................................4-22
4-31 ICLR Bit Definitions..................................................................................................................4-23
4-32 ICCR Bit Definitions .................................................................................................................4-23
4-33 ICIP Bit Definitions...................................................................................................................4-24
4-34 ICFP Bit Definitions..................................................................................................................4-24
4-35 ICPR Bit Definitions .................................................................................................................4-25
4-36 List of First–Level Interrupts ....................................................................................................4-27
4-37 RTTR Bit Definitions ................................................................................................................4-30
4-38 RTAR Bit Definitions ................................................................................................................4-30
4-39 RCNR Bit Definitions ...............................................................................................................4-31
4-40 RTSR Bit Definitions ................................................................................................................4-32
4-41 OSMR[x] Bit Definitions ...........................................................................................................4-36
4-42 OIER Bit Definitions.................................................................................................................4-36
4-43 OWER Bit Definitions...............................................................................................................4-37
4-44 OSCR Bit Definitions ...............................................................................................................4-37
4-45 OSSR Bit Definitions................................................................................................................4-38
4-46 PWM_CTRLn Bit Definitions....................................................................................................4-41
4-47 PWM_DUTYn Bit Definitions ...................................................................................................4-42
4-48 PWM_PERVALn Bit Definitions...............................................................................................4-43
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Contents
4-49 GPIO Register Addresses .......................................................................................................4-44
4-50 Interrupt Controller Register Addresses ..................................................................................4-45
4-51 RTC Register Addresses.........................................................................................................4-45
4-52 OS Timer Register Addresses.................................................................................................4-45
4-53 Pulse Width Modulator Register Addresses............................................................................4-46
5-1 DMAC Signal List ......................................................................................................................5-2
5-2 Channel Priority (if all channels are running concurrently)........................................................5-4
5-3 Channel Priority.........................................................................................................................5-4
5-4 Priority Schemes Examples.......................................................................................................5-5
5-5 DMA Quick Reference for Internal Peripherals .......................................................................5-13
5-6 DINT Bit Definitions .................................................................................................................5-17
5-7 DCSRx Bit Definitions..............................................................................................................5-18
5-8 DRCMRx Bit Definitions ..........................................................................................................5-20
5-9 DDADRx Bit Definitions...........................................................................................................5-21
5-10 DSADRx Bit Definitions ...........................................................................................................5-22
5-11 DTADRx Bit Definitions ...........................................................................................................5-23
5-12 DCMDx Bit Definitions .............................................................................................................5-24
5-13 DMA Controller Register Summary .........................................................................................5-28
6-1 Device Transactions ..................................................................................................................6-7
6-2 MDCNFG Bit Definitions............................................................................................................6-9
6-3 MDMRS Bit Definitions............................................................................................................6-12
6-4 MDMRSLP Register Bit Definitions .........................................................................................6-14
6-5 MDREFR Bit Definitions ..........................................................................................................6-15
6-6 Sample SDRAM Memory Size Options...................................................................................6-18
6-7 External to Internal Address Mapping for Normal Bank Addressing .......................................6-19
6-8 External to Internal Address Mapping for SA-1111 Addressing ..............................................6-21
6-9 Pin Mapping to SDRAM Devices with Normal Bank Addressing.............................................6-23
6-10 Pin Mapping to SDRAM Devices with SA1111 Addressing.....................................................6-25
6-11 SDRAM Command Encoding..................................................................................................6-28
6-12 SDRAM Mode Register Opcode Table....................................................................................6-28
6-13 SXCNFG Bit Definitions...........................................................................................................6-33
6-14 SXCNFG..................................................................................................................................6-36
6-15 Synchronous Static Memory External to Internal Address Mapping Options..........................6-37
6-16 SXMRS Bit Definitions.............................................................................................................6-38
6-17 Read Configuration Register Programming Values.................................................................6-40
6-18 Frequency Code Configuration Values Based on Clock Speed..............................................6-40
6-20 16-Bit Bus Write Access..........................................................................................................6-44
6-19 32-Bit Bus Write Access..........................................................................................................6-44
6-21 32-Bit Byte Address Bits MA[1:0] for Reads Based on DQM[3:0] ...........................................6-45
6-22 16-Bit Byte Address Bit MA[0] for Reads Based on DQM[1:0]................................................6-45
6-23 SA-1111 Register Bit Definitions .............................................................................................6-45
6-24 MSC0/1/2 Bit Definitions..........................................................................................................6-47
6-25 Asynchronous Static Memory and Variable Latency I/O Capabilities......................................6-50
6-26 MCMEM0/1 Bit Definitions.......................................................................................................6-60
6-27 MCATT0/1 Bit Definitions ........................................................................................................6-61
6-28 MCIO0/1 Bit Definitions ...........................................................................................................6-61
6-29 Card Interface Command Assertion Code Table.....................................................................6-62
6-30 MECR Bit Definition.................................................................................................................6-63
6-31 Common Memory Space Write Commands............................................................................6-65
6-32 Common Memory Space Read Commands............................................................................6-65
xviii Intel® PXA255 Processor Developer’s Manual
Contents
6-33 Attribute Memory Space Write Commands .............................................................................6-65
6-34 Attribute Memory Space Read Commands .............................................................................6-65
6-35 16-Bit I/O Space Write Commands (nIOIS16 = 0)...................................................................6-65
6-36 16-Bit I/O Space Read Commands (nIOIS16 = 0)...................................................................6-65
6-37 8-Bit I/O Space Write Commands (nIOIS16 = 1).....................................................................6-66
6-38 8-Bit I/O Space Read Commands (nIOIS16 = 1).....................................................................6-66
6-39 BOOT_SEL Definitions............................................................................................................6-74
6-40 BOOT_DEF Bitmap .................................................................................................................6-75
6-41 Valid Boot Configurations Based on Processor Type..............................................................6-75
6-42 Memory Controller Pin Reset Values.......................................................................................6-79
6-43 Memory Controller Register Summary ....................................................................................6-81
7-1 Pin Descriptions.........................................................................................................................7-4
7-2 LCD Controller Data Pin Utilization..........................................................................................7-21
7-3 LCCR0 Bit Definitions..............................................................................................................7-23
7-4 LCCR1 Bit Definitions..............................................................................................................7-26
7-5 LCCR2 Bit Definitions..............................................................................................................7-28
7-6 LCCR3 Bit Definitions..............................................................................................................7-31
7-7 FDADRx Bit Definitions............................................................................................................7-33
7-8 FSADRx Bit Definitions............................................................................................................7-34
7-9 FIDRx Bit Definitions................................................................................................................7-34
7-10 LDCMDx Bit Definitions ...........................................................................................................7-36
7-11 FBRx Bit Definitions.................................................................................................................7-37
7-12 LCSR Bit Definitions ................................................................................................................7-40
7-13 LIICR Bit Definitions.................................................................................................................7-41
7-14 TRGBR Bit Definitions .............................................................................................................7-42
7-15 TCR Bit Definitions ..................................................................................................................7-44
7-16 LCD Controller Register Summary ..........................................................................................7-44
8-1 External Interface to Codec .......................................................................................................8-1
8-2 SSCR0 Bit Definitions................................................................................................................8-9
8-3 SSCR1 Bit Definitions..............................................................................................................8-11
8-4 TFT and RFT Values for DMA Servicing .................................................................................8-15
8-5 SSDR Bit Definitions................................................................................................................8-15
8-6 SSSR Bit Definitions................................................................................................................8-17
8-7 SSP Controller Register Summary ..........................................................................................8-19
9-1 I2C Signal Description ...............................................................................................................9-1
9-2 I2C Bus Definitions ...................................................................................................................9-2
9-3 Modes of Operation ...................................................................................................................9-3
9-4 START and STOP Bit Definitions ..............................................................................................9-4
9-5 Master Transactions ................................................................................................................9-12
9-6 Slave Transactions ..................................................................................................................9-15
9-7 General Call Address Second Byte Definitions .......................................................................9-17
9-8 IBMR Bit Definitions................................................................................................................9-22
9-9 IDBR Bit Definitions ................................................................................................................9-23
9-10 ICR Bit Definitions...................................................................................................................9-23
9-11 ISR Bit Definitions...................................................................................................................9-26
9-12 ISAR Bit Definitions ................................................................................................................9-27
10-1 UART Signal Descriptions .......................................................................................................10-3
10-2 UART Register Addresses as Offsets of a Base .....................................................................10-6
10-3 RBR Bit Definitions ..................................................................................................................10-6
10-4 THR Bit Definitions ..................................................................................................................10-7
Intel® PXA255 Processor Developer’s Manual xix
Contents
10-5 DLL Bit Definitions...................................................................................................................10-8
10-6 DLH Bit Definitions ..................................................................................................................10-8
10-7 IER Bit Definitions....................................................................................................................10-9
10-8 Interrupt Conditions ...............................................................................................................10-10
10-9 IIR Bit Definitions...................................................................................................................10-10
10-10 Interrupt Identification Register Decode ................................................................................10-11
10-11 FCR Bit Definitions ................................................................................................................10-12
10-12 LCR Bit Definitions ................................................................................................................10-14
10-13 LSR Bit Definitions.................................................................................................................10-15
10-14 MCR Bit Definitions ...............................................................................................................10-18
10-15 MSR Bit Definitions................................................................................................................10-20
10-16 SPR Bit Definitions ................................................................................................................10-21
10-17 ISR Bit Definitions..................................................................................................................10-24
10-18 FFUART Register Summary..................................................................................................10-26
10-19 BTUART Register Summary .................................................................................................10-26
10-20 STUART Register Summary .................................................................................................10-27
10-21 Flow Control Registers in BTUART and STUART.................................................................10-28
11-1 FICP Signal Description ..........................................................................................................11-1
11-2 ICCR0 Bit Definitions...............................................................................................................11-8
11-3 ICCR1 Bit Definitions.............................................................................................................11-10
11-4 ICCR2 Bit Definitions.............................................................................................................11-11
11-5 ICRD Bit Definitions...............................................................................................................11-12
11-6 ICSR0 Bit Definitions.............................................................................................................11-13
11-7 ICSR1 Bit Definitions.............................................................................................................11-15
11-8 FICP Register Summary........................................................................................................11-16
12-1 Endpoint Configuration............................................................................................................12-2
12-2 USB States..............................................................................................................................12-3
12-3 IN, OUT, and SETUP Token Packet Format ...........................................................................12-5
12-4 SOF Token Packet Format......................................................................................................12-5
12-5 Data Packet Format.................................................................................................................12-6
12-6 Handshake Packet Format ......................................................................................................12-6
12-7 Bulk Transaction Formats........................................................................................................12-7
12-8 Isochronous Transaction Formats...........................................................................................12-7
12-9 Control Transaction Formats ................................................................................................... 12-7
12-10 Interrupt Transaction Formats .................................................................................................12-8
12-11 Host Device Request Summary ..............................................................................................12-9
12-12 UDCCR Bit Definitions...........................................................................................................12-22
12-13 UDC Control Function Register.............................................................................................12-24
12-14 UDCCS0 Bit Definitions.........................................................................................................12-25
12-15 UDCCS1/6/11 Bit Definitions.................................................................................................12-27
12-16 UDCCS2/7/12 Bit Definitions.................................................................................................12-29
12-17 UDCCS3/8/13 Bit Definitions.................................................................................................12-31
12-18 UDCCS4/9/14 Bit Definitions.................................................................................................12-33
12-19 UDCCS5/10/15 Bit Definitions...............................................................................................12-34
12-20 UICR0 Bit Definitions.............................................................................................................12-37
12-21 UICR1 Bit Definitions.............................................................................................................12-38
12-22 USIR0 Bit Definitions.............................................................................................................12-39
12-23 USIR1 Bit Definitions.............................................................................................................12-41
12-24 UFNHR Bit Definitions...........................................................................................................12-43
12-25 UFNLR Bit Definitions............................................................................................................12-44
xx Intel® PXA255 Processor Developer’s Manual
Contents
12-26 UBCR2/4/7/9/12/14 Bit Definitions.........................................................................................12-45
12-27 UDDR0 Bit Definitions ...........................................................................................................12-46
12-28 UDDR1/6/11 Bit Definitions ...................................................................................................12-46
12-29 UDDR2/7/12 Bit Definitions ...................................................................................................12-47
12-30 UDDR3/8/13 Bit Definitions ...................................................................................................12-47
12-31 UDDR4/9/14 Bit Definitions ...................................................................................................12-48
12-32 UDDR5/10/15 Bit Definitions .................................................................................................12-48
12-33 USB Device Controller Register Summary............................................................................12-48
13-1 External Interface to CODECs.................................................................................................13-2
13-2 Supported Data Stream Formats.............................................................................................13-3
13-3 Slot 1 Bit Definitions.................................................................................................................13-7
13-4 Slot 2 Bit Definitions.................................................................................................................13-7
13-5 Input Slot 1 Bit Definitions......................................................................................................13-10
13-6 Input Slot 2 Bit Definitions......................................................................................................13-11
13-7 GCR Bit Definitions................................................................................................................13-20
13-8 GSR Bit Definitions................................................................................................................13-22
13-9 POCR Bit Definitions .............................................................................................................13-23
13-10 PICR Bit Definitions ...............................................................................................................13-24
13-11 POSR Bit Definitions..............................................................................................................13-25
13-12 PISR Bit Definitions ...............................................................................................................13-25
13-13 CAR Bit Definitions ................................................................................................................13-26
13-14 PCDR Bit Definitions..............................................................................................................13-26
13-15 MCCR Bit Definitions.............................................................................................................13-27
13-16 MCSR Bit Definitions .............................................................................................................13-28
13-17 MCDR Bit Definitions.............................................................................................................13-28
13-18 MOCR Bit Definitions.............................................................................................................13-29
13-19 MICR Bit Definitions...............................................................................................................13-30
13-20 MOSR Bit Definitions.............................................................................................................13-30
13-21 MISR Bit Definitions...............................................................................................................13-31
13-22 MODR Bit Definitions.............................................................................................................13-31
13-23 Address Mapping for CODEC Registers ...............................................................................13-33
13-24 Register Mapping Summary ..................................................................................................13-35
14-1 External Interface to CODEC...................................................................................................14-2
14-2 Supported Sampling Frequencies ...........................................................................................14-6
14-3 SACR0 Bit Definitions..............................................................................................................14-9
14-4 FIFO Write/Read table...........................................................................................................14-10
14-5 TFTH and RFTH Values for DMA Servicing ..........................................................................14-10
14-6 SACR1 Bit Definitions............................................................................................................14-11
14-7 SASR0 Bit Definitions ............................................................................................................14-12
14-8 SADIV Bit Definitions.............................................................................................................14-13
14-9 SAICR Bit Definitions.............................................................................................................14-13
14-10 SAIMR Bit Descriptions .........................................................................................................14-14
14-11 SADR Bit Descriptions...........................................................................................................14-14
14-12 Register Memory Map ...........................................................................................................14-16
15-1 Command Token Format.........................................................................................................15-2
15-2 MMC Data Token Format ........................................................................................................15-2
15-3 SPI Data Token Format...........................................................................................................15-2
15-4 MMC Signal Description ..........................................................................................................15-6
15-5 MMC_STRPCL Bit Definitions...............................................................................................15-23
15-6 MMC_STAT Bit Definitions....................................................................................................15-23
Intel® PXA255 Processor Developer’s Manual xxi
15-7 MMC_CLK Bit Definitions......................................................................................................15-25
15-8 MMC_SPI Bit Definitions .......................................................................................................15-25
15-9 MMC_CMDAT Bit Definitions ................................................................................................15-26
15-10 MMC_RESTO Bit Definitions.................................................................................................15-27
15-11 MMC_RDTO Register ...........................................................................................................15-28
15-12 MMC_BLKLEN Bit Definitions ...............................................................................................15-29
15-13 MMC_NOB Bit Definitions ..................................................................................................... 15-29
15-14 MMC_PRTBUF Bit Definitions...............................................................................................15-30
15-15 MMC_I_MASK Bit Definitions................................................................................................15-30
15-16 MMC_I_REG Bit Definitions ..................................................................................................15-32
15-17 MMC_CMD Register ............................................................................................................. 15-33
15-18 Command Index Values ........................................................................................................15-33
15-19 MMC_ARGH Bit Definitions...................................................................................................15-35
15-20 MMC_ARGL Bit Definitions ................................................................................................... 15-35
15-21 MMC_RES, FIFO Entry .........................................................................................................15-36
15-22 MMC_RXFIFO, FIFO Entry ...................................................................................................15-36
15-23 MMC_TXFIFO, FIFO Entry....................................................................................................15-37
15-24 MMC Controller Registers .....................................................................................................15-37
16-1 SSP Serial Port I/O Signals.....................................................................................................16-2
16-2 Programmable Serial Protocol (PSP) Parameters ................................................................16-12
16-3 SSCR0 Bit Definitions............................................................................................................16-19
16-4 SSCR1 Bit Definitions............................................................................................................16-21
16-5 SSPSP Bit Definitions............................................................................................................16-23
16-6 SSTO Bit Definitions..............................................................................................................16-24
16-7 SSITR Bit Definitions.............................................................................................................16-25
16-8 SSSR Bit Definitions..............................................................................................................16-26
16-9 SSDR Bit Definitions..............................................................................................................16-29
16-10 NSSP Register Address Map ................................................................................................16-29
17-1 UART Signal Descriptions.......................................................................................................17-3
17-2 RBR Bit Definitions................................................................................................................17-10
17-3 THR Bit Definitions ................................................................................................................17-10
17-4 DLL Bit Definitions.................................................................................................................17-11
17-5 Divisor Latch Register High (DLH) Bit Definitions ................................................................. 17-11
17-6 IER Bit Definitions..................................................................................................................17-12
17-7 Interrupt Conditions ...............................................................................................................17-13
17-8 IIR Bit Definitions...................................................................................................................17-13
17-9 Interrupt Identification Register Decode ................................................................................17-14
17-10 FCR Bit Definitions ................................................................................................................17-15
17-11 FOR Bit Definitions................................................................................................................17-16
17-12 ABR Bit Definitions ................................................................................................................17-17
17-13 ACR Bit Definitions................................................................................................................17-18
17-14 LCR Bit Definitions ................................................................................................................17-18
17-15 LSR Bit Definitions.................................................................................................................17-20
17-16 MCR Bit Definitions ...............................................................................................................17-22
17-17 MSR Bit Definitions................................................................................................................17-23
17-18 SCR Bit Definitions................................................................................................................17-24
17-19 ISR Bit Definitions..................................................................................................................17-25
17-20 HWUART Register Locations................................................................................................17-25
Revision History
Date Revision Description
March 2003 -001 Initial release
January 2004 -002
Contents
Replaced Table 12-13
Modified SSPFRM behavior
Added note to Table 3-1 about supported frequencies
Explained RDY_sync signal
Correct GPIO numbers in Table 4-35
Changed behavior of GPIO pins out of reset
Added Polling directions for I2C
Intel® PXA255 Processor Developer’s Manual xxiii
Contents
xxiv Intel® PXA255 Processor Developer’s Manual
Introduction 1
This document applies to the Intel® PXA255 Processor (PXA255 processor). It is an application
specific standard product (ASSP) that provides industry-leading MIPS/mW performance for
handheld computing applications. The processor is a highly integrated system on a chip and
includes a high-performance low-power Intel XScale® microarchitecture with a variety of
different system peripherals.
The PXA255 processor is a 17x17mm 256-pin PBGA package configuration for high performance.
The 17x17mm package has a 32-bit memory data bus and the full assortment of peripherals.
1.1 Intel XScale® Microarchitecture Features
The Intel XScale® microarchitecture provides these features:
• ARM* Architecture Version 5TE ISA compliant.
— ARM* Thumb Instruction Support
— ARM* DSP Enhanced Instructions
• Low power consumption and high performance
• Intel® Media Processing Technology
— Enhanced 16-bit Multiply
— 40-bit Accumulator
• 32-KByte Instruction Cache
• 32-KByte Data Cache
• 2-KByte Mini Data Cache
• 2-KByte Mini Instruction Cache
• Instruction and Data Memory Management Units
• Branch Target Buffer
• Debug Capability via JTAG Port
Refer to the Intel XScale® Microarchitecture for the Intel® PXA255 Processor User’s Manual for
more details.
1.2 System Integration Features
The processor integrates the Intel XScale® microarchitecture with this peripheral set:
• Memory Controller
• Clock and Power Controllers
• Universal Serial Bus Client
Intel® PXA255 Processor Developer’s Manual 1-1
Introduction
• DMA Controller
• LCD Controller
• AC97
2
• I
S
• MultiMediaCard
• FIR Communication
• Synchronous Serial Protocol Port
2
• I
C
• General Purpose I/O pins
• UARTs
• Real-Time Clock
• OS Timers
• Pulse Width Modulation
• Interrupt Control
1.2.1 Memory Controller
The Memory Controller provides glueless control signals with programmable timing for a wide
assortment of memory-chip types and organizations. It supports up to four SDRAM partitions; six
static chip selects for SRAM, SSRAM, Flash, ROM, SROM, and companion chips; support for two
PCMCIA or Compact Flash slots
1.2.2 Clocks and Power Controllers
The processor functional blocks are driven by clocks that are derived from a 3.6864-MHz crystal
and an optional 32.768-kHz crystal.
The 3.6864-MHz crystal drives a core Phase Locked Loop (PLL) and a Peripheral PLL. The PLLs
produce selected clock frequencies to run particular functional blocks.
The 32.768-kHz crystal provides an optional clock source that must be selected after a hard reset.
This clock drives the Real Time Clock (RTC), Power Management Controller, and Interrupt
Controller. The 32.768-kHz crystal is on a separate power island to provide an active clock while
the processor is in sleep mode.
Power management controls the transition between the turbo/run, idle, and sleep operating modes.
1.2.3 Universal Serial Bus (USB) Client
The USB Client Module is based on the Universal Serial Bus Specification, Revision 1.1. It
supports up to sixteen endpoints and it provides an internally generated 48-MHz clock. The USB
Device Controller provides FIFOs with DMA access to or from memory.
1-2 Intel® PXA255 Processor Developer’s Manual
1.2.4 DMA Controller (DMAC)
The DMAC provides sixteen prioritized channels to service transfer requests from internal
peripherals and up to two data transfer requests from external companion chips. The DMAC is
descriptor-based to allow command chaining and looping constructs.
The DMAC operates in Flow-Through Mode when performing peripheral-to-memory, memory-toperipheral, and memory-to-memory transfers. The DMAC is compatible with peripherals that use
word, half-word, or byte data sizes.
1.2.5 LCD Controller
The LCD Controller supports both passive (DSTN) and active (TFT) flat-panel displays with a
maximum supported resolution of 640x480x16-bit/pixel. An internal 256 entry palette expands 1,
2, 4, or 8-bit encoded pixels. Non-encoded 16-bit pixels bypass the palette.
Two dedicated DMA channels allow the LCD Controller to support single- and dual-panel
displays. Passive monochrome mode supports up to 256 gray-scale levels and passive color mode
supports up to 64K colors. Active color mode supports up to 64K colors.
Introduction
1.2.6 AC97 Controller
The AC97 Controller supports AC97 Revision 2.0 CODECs. These CODECs can operate at
sample rates up to 48 KHz. The controller provides independent 16-bit channels for Stereo PCM
In, Stereo PCM Out, Modem In, Modem Out, and mono Microphone In. Each channel includes a
FIFO that supports DMA access to memory.
1.2.7 Inter-IC Sound (I2S) Controller
The I2S Controller provides a serial link to standard I2S CODECs for digital stereo sound. It
supports both the Normal-I
connection to an I
The controller includes FIFOs that support DMA access to memory.
2
S CODEC. I2S Controller signals are multiplexed with AC97 Controller pins.
2
S and MSB-Justified I2S formats, and provides four signals for
1.2.8 Multimedia Card (MMC) Controller
The MMC Controller provides a serial interface to standard memory cards. The controller supports
up to two cards in either MMC or SPI modes with serial data transfers up to 20 Mbps. The MMC
controller has FIFOs that support DMA access to and from memory.
1.2.9 Fast Infrared (FIR) Communication Port
The FIR Communication Port is based on the 4-Mbps Infrared Data Association (IrDA)
Specification. It operates at half-duplex and has FIFOs with DMA access to memory. The FIR
Communication Port uses the STUART’s transmit and receive pins to directly connect to external
IrDA LED transceivers.
Intel® PXA255 Processor Developer’s Manual 1-3
Introduction
1.2.10 Synchronous Serial Protocol Controller (SSPC)
The SSP Port provides a full-duplex synchronous serial interface that operates at bit rates from
7.2 kHz to 1.84 MHz. It supports National Semiconductor’s Microwire*, Texas Instruments’
Synchronous Serial Protocol*, and Motorola’s Serial Peripheral Interface*. The SSPC has FIFOs
with DMA access to memory.
1.2.11 Inter-Integrated Circuit (I2C) Bus Interface Unit
The I2C Bus Interface Unit provides a general purpose 2-pin serial communication port.The
interface uses one pin for data and address and a second pin for clocking.
1.2.12 GPIO
Each GPIO pin can be individually programmed as an output or an input. Inputs can cause
interrupts on rising or falling edges. Primary GPIO pins are not shared with peripherals while
secondary GPIO pins have alternate functions which can be mapped to the peripherals.
1.2.13 UARTs
The processor provides three Universal Asynchronous Receiver/Transmitters. Each UART can be
used as a slow infrared (SIR) transmitter/receiver based on the Infrared Data Association Serial
Infrared (SIR) Physical Layer Link Specification.
1.2.13.1 Full Function UART (FFUART)
The FFUART baud rate is programmable up to 230 Kbps. The FFUART provides a complete set of
modem control pins: nCTS, nRTS, nDSR, nDTR, nRI, and nDCD. It has FIFOs with DMA access
to or from memory.
1.2.13.2 Bluetooth UART (BTUART)
The BTUART baud rate is programmable up to 921 Kbps. The BTUART provides a partial set of
modem control pins: nCTS and nRTS. Other modem control pins can be implemented via GPIOs.
The BTUART has FIFOs with DMA access to or from memory.
1.2.13.3 Standard UART (STUART)
The STUART baud rate is programmable up to 230 Kbps. The STUART does not provide any
modem control pins. The modem control pins can be implemented via GPIOs. The STUART has
FIFOs with DMA access to or from memory.
The STUART’s transmit and receive pins are multiplexed with the Fast Infrared Communication
Port.
1-4 Intel® PXA255 Processor Developer’s Manual
1.2.13.4 Hardware UART (HWUART)
The PXA255 processor has a UART with hardware flow control. The HWUART provides a partial
set of modem control pins: nCTS and nRTS. These modem control pins provide full hardware flow
control. Other modem control pins can be implemented via GPIOs. The HWUART baud rate is
programmable up to 921.6 Kbps.
The HWUART’s pins are multiplexed with the PCMCIA control pins. Because of this, these
HWUART pins operate at the same voltage as the memory bus. Also, since the PCMCIA pin
nPWE is used for variable-latency input/output (VLIO), while using these pins for the HWUART,
VLIO is unavailable. The HWUART pins are also available over the BTUART pins. When
operating over the BTUART pins, the HWUART pins operate at the I/O voltage.
1.2.14 Real-Time Clock (RTC)
The Real-Time Clock can be clocked from either crystal. A system with a 32.768-KHz crystal
consumes less power during Sleep versus a system using only the 3.6864-MHz crystal. This crystal
can be removed to save system cost. The RTC provides a constant frequency output with a
programmable alarm register. This alarm register can be used to wake up the processor from Sleep
mode.
Introduction
1.2.15 OS Timers
The OS Timers can be used to provide a 3.68-MHz reference counter with four match registers.
These registers can be configured to cause interrupts when equal to the reference counter. One
match register can be used to cause a watchdog reset.
1.2.16 Pulse-Width Modulator (PWM)
The PWM has two independent outputs that can be programmed to drive two GPIOs. The
frequency and duty cycle are independently programmable. For example, one GPIO can control
LCD contrast and the other LCD brightness.
1.2.17 Interrupt Control
The Interrupt Controller directs the processor interrupts into the core’s IRQ and FIQ inputs. The
Mask Register enables or disables individual interrupt sources.
1.2.18 Network Synchronous Serial Protocol Port
The PXA255 processor has an SSP port optimized for connection to other network ASICs. This
NSSP adds a Hi-Z function to TXD, the ability to control when Hi-Z occurs, and swapping the
TXD/RXD pins.
This port is not multiplexed with other interfaces.
Intel® PXA255 Processor Developer’s Manual 1-5
Introduction
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