SGS Thomson Microelectronics PSD835G2, PSD835G2V Datasheet

Confi gurabl e Memory Syst em on a C hi p

FEATURES SUMMARY

■ 5 V±10% Single Supply Voltage:

■ Up to 4 Mbit of Primary Flash Memory (8

uniform sectors)

■ 256Kbit Secondary Flash Memory (4 uniform

sectors)

■ Up to 64 Kbit SRAM

■ Over 3,000 Gates of PLD: DPLD and CPLD

■ 52 Reconfigurable I/O ports

■ Enhanced JTAG Serial Port

■ Programmable power management

■ High Endurance:

– 100,000 Erase/Write Cycles of Flash Memory – 1,000 Erase/Write Cycles of PLD

PSD835G2

for 8-Bit Microcontrollers

PRELIMINARY DATA

Figure 1. Packages

TQFP80 (U)

January 2002

This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to change without notice.

1/3

1.0 Introduction

PSD8XX Family

PSD835G2

Configurable Memory System on a Chip for 8-Bit Microcontrollers

The PSD8XX series of Programmable Microcontroller (MCU) Peripherals brings In-System-Programmability (ISP) to Flash memory and programmable logic. The result is a simple and flexible solution for embedded designs. PSD8XX devices combine many of the peripheral functions found in MCU based applications:

• 4 Mbit of Flash memory

• A secondary Flash memory for boot or data

• Over 3,000 gates of Flash programmable logic

• 64 Kbit SRAM

• Reconfigurable I/O ports

• Programmable power management.

PSD8XX Family PSD835G2

1.0 Introduction

(Cont.)

Please refer to the revision block at the end of this document for updated information.

The PSD835G2 device offers two methods to program PSD Flash memory while the PSD is soldered to a circuit board.

❏ In-System Programming (ISP) via JTAG

An IEEE 1149.1 compliant JTAG-ISP interface is included on the PSD enabling the entire device (both flash memories, the PLD, and all configuration) to be rapidly programmed while soldered to the circuit board. This requires no MCU participation, which means the PSD can be programmed anytime, even while completely blank.

The innovative JTAG interface to flash memories is an industry first, solving key problems faced by designers and manufacturing houses, such as:

• First time programming – How do I get firmware into the flash the very first time?

JTAG is the answer, program the PSD while blank with no MCU involvement.

• Inventory build-up of pre-programmed devices – How do I maintain an accurate

count of pre-programmed flash memory and PLD devices based on customer demand? How many and what version? JTAG is the answer, build your hardware with blank PSDs soldered directly to the board and then custom program just before they are shipped to customer. No more labels on chips and no more wasted inventory.

• Expensive sockets – How do I eliminate the need for expensive and unreliable

sockets? JTAG is the answer. Solder the PSD directly to the circuit board. Program first time and subsequent times with JTAG. No need to handle devices and bend the fragile leads.

❏ In-Application re-Programming (IAP)

Two independent flash memory arrays are included so the MCU can execute code from one memory while erasing and programming the other. Robust product firmware updates in the field are possible over any communication channel (CAN, Ethernet, UART, J1850, etc) using this unique architecture. Designers are relieved of these problems:

• Simultaneous read and write to flash memory – How can the MCU program the

same memory from which it is executing code? It cannot. The PSD allows the MCU to operate the two flash memories concurrently, reading code from one while erasing and programming the other during IAP.

• Complex memory mapping – How can I map these two memories efficiently?

A Programmable Decode PLD is embedded in the PSD. The concurrent PSD memories can be mapped anywhere in MCU address space, segment by segment with extremely high address resolution. As an option, the secondary flash memory can be swapped out of the system memory map when IAP is complete. A built-in page register breaks the MCU address limit.

• Separate program and data space – How can I write to flash memory while it

resides in “program” space during field firmware updates, my 80C51 won’t allow it The flash PSD provides means to “reclassify” flash memory as “data” space during IAP, then back to “program” space when complete.

PSDsoft – ST’s software development tool – guides you through the design process step-by-step making it possible to complete an embedded MCU design capable of ISP/IAP in just hours. Select your MCU and PSDsoft will take you through the remainder of the design with point and click entry, covering...PSD selection, pin definitions, programmable logic inputs and outputs, MCU memory map definition, ANSI C code generation for your MCU, and merging your MCU firmware with the PSD design. When complete, two different device programmers are supported directly from PSDsoft – FlashLINK (JTAG) and PSDpro.

The PSD835G2 is available in an 80-pin TQFP package.

PSD835G2 PSD8XX Family

❏ A simple interface to 8-bit microcontrollers that use either multiplexed or

non-multiplexed busses. The bus interface logic uses the control signals generated by the microcontroller automatically when the address is decoded and a read or write is performed. A partial list of the MCU families supported include:

• Intel 8031, 80196, 80188, 80C251

• Motorola 68HC11 and 68HC16

• Philips 8031 and 80C51XA

• Zilog Z80, Z8 and Z180

• Infineon C500 family

❏ 4 Mbit Flash memory. This is the main Flash memory. It is divided into eight

equal-sized blocks that can be accessed with user-specified addresses.

❏ Internal secondary 256 Kbit Flash boot memory. It is divided into four equal-sized

blocks that can be accessed with user-specified addresses. This secondary memory brings the ability to execute code and update the main Flash concurrently.

❏ 64 Kbit SRAM. The SRAM’s contents can be protected from a power failure by

connecting an external battery.

❏ CPLD with 16 Output Micro⇔Cells (OMCs) and 24 Input Micro⇔Cells (IMCs). The

CPLD may be used to efficiently implement a variety of logic functions for internal and external control. Examples include state machines, loadable shift registers, and loadable counters. The CPLD can also generate eight external chip selects.

❏ Decode PLD (DPLD) that decodes address for selection of internal memory blocks. ❏ 52 individually configurable I/O port pins that can be used for the following functions:

• MCU I/Os

• PLD I/Os

• Latched MCU address output

• Special function I/Os.

• I/O ports may be configured as open-drain outputs.

❏ Standby current as low as 50 µA for 5 V devices. ❏ Built-in JTAG compliant serial port allows full-chip In-System Programmability (ISP).

With it, you can program a blank device or reprogram a device in the factory or the field.

❏ Internal page register that can be used to expand the microcontroller address space

by a factor of 256.

❏ Internal programmable Power Management Unit (PMU) that supports a low power

mode called Power Down Mode. The PMU can automatically detect a lack of microcontroller activity and put the PSD8XX into Power Down Mode.

❏ Erase/Write cycles:

• Flash memory – 100,000 minimum

• PLD – 1,000 minimum

2.0 Key Features

3.0 PSD8XX Series

Part # Flash

Flash Main Boot

Serial ISP Memory Memory

PSD8XX I/O PLD Input Output PLD JTAG/ISP Kbit Kbit SRAM Supply

Series Device Pins Inputs Macrocells Macrocells Outputs Port 8 Sectors (4 Sectors) Kbit Voltage

PSD835G2 52 24 16 24 Yes 4096 256 64 5V

PSD8XX PSD813F2 27 57 24 16 19 Yes 1024 256 16 5V

PSD834F2 27 57 24 16 19 Yes 2048 256 64 5V PSD833F2 27 57 24 16 19 Yes 1024 256 64 5V

Table 1. PSD8XX Product Matrix

PSD8XX Family PSD835G2

PROG.

MCU BUS

INTRF.

ADIO

PORT

CNTL0, CNTL1, CNTL2

AD0 – AD15

CLKIN

PORT F

CLKIN

PLD

INPUT

BUS

PROG.

PORT

PROG.

PORT

POWER

MANGMT

UNIT

4 MBIT MAIN FLASH

MEMORY

8 SECTORS

VSTDBY

PA0 – PA7

PROG.

PORT

PROG.

PORT

PROG.

PORT

PB0 – PB7

PROG.

PORT

PROG.

PORT

PF0 – PF7

PG0 – PG7

PE0 – PE7

PC0 – PC7

PD0 – PD3

ADDRESS/DATA/CONTROL BUS

PORT A & B

8 EXT CS to PORT C or F

24 INPUT MICRO⇔CELLS

PORT A ,B & C

256 KBIT SECONDARY

FLASH MEMORY (BOOT OR DATA)

4 SECTORS

64 KBIT BATTERY

BACKUP SRAM

RUNTIME CONTROL AND I/O REGISTERS

SRAM SELECT

PERIP I/O MODE SELECTS

MICRO⇔CELL FEEDBACK OR PORT INPUT

CSIOP

FLASH ISP CPLD

(CPLD)

16 OUTPUT MICRO⇔CELLS

FLASH DECODE

PLD (DPLD

)

PLD, CONFIGURATION

& FLASH MEMORY

LOADER

JTAG

SERIAL

CHANNEL

(

PE6

)

PAGE

EMBEDDED

ALGORITHM

SECTOR SELECTS

GLOBAL CONFIG. & SECURITY

Figure 1. PSD835G2 Block Diagram

*Additional address lines can be brought into PSD via Port A, B, C, D, or F.

PSD835G2 PSD8XX Family

PSD8XX devices contain several major functional blocks. Figure 1 on page 3 shows the architecture of the PSD8XX device family. The functions of each block are described briefly in the following sections. Many of the blocks perform multiple functions and are user configurable.

4.1 Memory

The PSD835G2 contains the following memories:

• 4 Mbit Flash

• A secondary 256 Kbit Flash memory for boot or data

• 64 Kbit SRAM.

Each of the memories is briefly discussed in the following paragraphs. A more detailed discussion can be found in section 9.

The 4 Mbit Flash is the main memory of the PSD835G2. It is divided into eight equally-sized sectors that are individually selectable.

The 256 Kbit secondary Flash memory is divided into four equally-sized sectors. Each sector is individually selectable.

The 64 Kbit SRAM is intended for use as a scratchpad memory or as an extension to the microcontroller SRAM. If an external battery is connected to the PSD8XX’s Vstby pin, data will be retained in the event of a power failure.

Each block of memory can be located in a different address space as defined by the user. The access times for all memory types includes the address latching and DPLD decoding time.

4.2 PLDs

The device contains two PLD blocks, each optimized for a different function, as shown in Table 2. The functional partitioning of the PLDs reduces power consumption, optimizes cost/performance, and eases design entry.

The Decode PLD (DPLD) is used to decode addresses and generate chip selects for the PSD835G2 internal memory and registers. The CPLD can implement user-defined logic functions. The DPLD has combinatorial outputs. The CPLD has 16 Output Micro⇔Cells and 8 combinatorial outputs. The PSD835G2 also has 24 Input Micro⇔Cells that can be configured as inputs to the PLDs. The PLDs receive their inputs from the PLD Input Bus and are differentiated by their output destinations, number of Product Terms, and Micro⇔Cells.

The PLDs consume minimal power by using Zero-Power design techniques. The speed and power consumption of the PLD is controlled by the Turbo Bit in the PMMR0 register and other bits in the PMMR2 registers. These registers are set by the microcontroller at runtime. There is a slight penalty to PLD propagation time when invoking the non-Turbo bit.

4.3 I/O Ports

The PSD835G2 has 52 I/O pins divided among seven ports (Port A, B, C, D, E, F and G). Each I/O pin can be individually configured for different functions. Ports can be configured as standard MCU I/O ports, PLD I/O, or latched address outputs for microcontrollers using multiplexed address/data busses.

The JTAG pins can be enabled on Port E for In-System Programming (ISP). Ports F and G can also be configured as a data port for a non-multiplexed bus.

4.4 Microcontroller Bus Interface

The PSD835G2 easily interfaces with most 8-bit microcontrollers that have either multiplexed or non-multiplexed address/data busses. The device is configured to respond to the microcontroller’s control signals, which are also used as inputs to the PLDs. Section

9.3.5 contains microcontroller interface examples.

4.0 PSD8XX Architectural Overview

Name Abbreviation Inputs Outputs Product Terms

Decode PLD DPLD 82 17 43 Complex PLD CPLD 82 24 150

Table 2. PLD I/O Table

PSD8XX Architectural Overview

(cont.)

4.5 ISP via JTAG Port

In-System Programming can be performed through the JTAG pins on Port E. This serial interface allows complete programming of the entire PSD835G2 device. A blank device can be completely programmed. The JTAG signals (TMS, TCK, TSTAT, TERR, TDI, TDO) can be multiplexed with other functions on Port E. Table 3 indicates the JTAG signals pin assignments.

4.6 In-System Programming (ISP)

Using the JTAG signals on Port E, the entire PSD835G2 (memory, logic, configuration) device can be programmed or erased without the use of the microcontroller.

Port E Pins JTAG Signal

PE0 TMS PE1 TCK PE2 TDI PE3 TDO PE4 TSTAT PE5 TERR

Table 3. JTAG Signals on Port E

PSD8XX Family PSD835G2

4.7 In-Application re-Programming (IAP)

The main Flash memory can also be programmed in-system by the microcontroller executing the programming algorithms out of the secondary Flash memory, or SRAM. Since this is a sizable separate block, the application can also continue to operate. The secondary Flash boot memory can be programmed the same way by executing out of the main Flash memory. Table 4 indicates which programming methods can program different functional blocks of the PSD8XX.

Device

Functional Block JTAG-ISP Programmer IAP

Main Flash memory Yes Yes Yes Flash Boot memory Yes Yes Yes PLD Array (DPLD and CPLD) Yes Yes No PSD Configuration Yes Yes No

Table 4. Methods of Programming Different Functional Blocks of the PSD835G2

4.8 Page Register

The eight-bit Page Register expands the address range of the microcontroller by up to 256 times.The paged address can be used as part of the address space to access external memory and peripherals or internal memory and I/O. The Page Register can also be used to change the address mapping of blocks of Flash memory into different memory spaces for IAP.

4.9 Power Management Unit

The Power Management Unit (PMU) in the PSD835G2 gives the user control of the power consumption on selected functional blocks based on system requirements. The PMU includes an Automatic Power Down unit (APD) that will turn off device functions due to microcontroller inactivity. The APD unit has a Power Down Mode that helps reduce power consumption.

The PSD835G2 also has some bits that are configured at run-time by the MCU to reduce power consumption of the CPLD. The turbo bit in the PMMR0 register can be turned off and the CPLD will latch its outputs and go to standby until the next transition on its inputs. Additionally, bits in the PMMR2 register can be set by the MCU to block signals from entering the CPLD to reduce power consumption. See section 9.5.

PSD835G2 PSD8XX Family

Define General Purpose

Logic in CPLD

Merge MCU Firmware

with PSD Configuration

PSD Programmer

*.OBJ FILE

Point and click definition of

combinatorial and registered logic

in CPLD. Access to HDL is

available if needed.

Define PSD Pin and

Node functions

Point and click definition of

PSD pin functions, internal nodes,

and MCU system memory map.

Choose MCU and PSD

Automatically Configures MCU

bus interface and other PSD

attributes.

PSDPro or

FlashLink (JTAG)

A composite object file is created

containing MCU firmware and

PSD configuration.

C Code Generation

Generate C Code

Specific to PSD

Finctions

User's choice of

Microcontroller

Compiler/Linker

*.OBJ file

available

for 3rd party

programmers

(Conventional or JTAG-ISP)

MCU Firmware

Hex or S-Record

format

Figure 2. PSDsoft Development Tool

5.0 Development System

The PSD8XX series is supported by PSDsoft a Windows-based (95, 98, NT) software development tool. A PSD design is quickly and easily produced in a point and click environment. The designer does not need to enter Hardware Definition Language (HDL) equations (unless desired) to define PSD pin functions and memory map information. The general design flow is shown in Figure 2 below. PSDsoft is available from our web site (www.st.com/psm) or other distribution channels.

PSDsoft directly supports two low cost device programmers from ST. PSDpro and FlashLINK (JTAG). Both of these programmers may be purchased through your local rep/distributor, or directly from our web site using a credit card. The PSD8XX is also supported by third party device programmers, see web site for current list.

PSD8XX Family PSD835G2

The following table describes the pin names and pin functions of the PSD835G2. Pins that have multiple names and/or functions are defined using PSDsoft.

6.0 Table 5. PSD835G2 Pin Descriptions

Pin*

(TQFP

Pin Name Pkg.) Type Description

ADIO0-7 3-7 I/O This is the lower Address/Data port. Connect your MCU

10-12 address or address/data bus according to the following rules:

1. If your MCU has a multiplexed address/data bus where the data is multiplexed with the lower address bits, connect AD[0:7] to this port.

2. If your MCU does not have a multiplexed address/data bus, connect A[0:7] to this port.

3. If you are using an 80C51XA in burst mode, connect A4/D0 through A11/D7 to this port.

ALE or AS latches the address. The PSD drives data out only if the read signal is active and one of the PSD functional blocks was selected. The addresses on this port are passed to the PLDs.

ADIO8-15 13-20 I/O This is the upper Address/Data port. Connect your MCU

address or address/data bus according to the following rules:

1. If your MCU has a multiplexed address/data bus where the data is multiplexed with the lower address bits, connect A[8:15 ] to this port.

2. If your MCU does not have a multiplexed address/data bus, connect A[8:15 ] to this port.

3. If you are using an 80C251 in page mode, connect AD[8:15] to this port

4. If you are using an 80C51XA in burst mode, connect A[12:19] to this port.

ALE or AS latches the address. The PSD drives data out only if the read signal is active and one of the PSD functional blocks was selected. The addresses on this port are passed to the PLDs.

CNTL0 59 I The following control signals can be connected to this port,

based on your MCU:

1. WR — active-low write input.

2. R_W — active-high read/active low write input.

This pin is connected to the PLDs. Therefore, these signals can be used in decode and other logic equations.

CNTL1 60 I The following control signals can be connected to this port,

based on your MCU:

1. RD — active-low read input.

2. E — E clock input.

3. DS — active-low data strobe input.

4. PSEN — connect PSEN to this port when it is being used as an active-low read signal. For example, when the 80C251 outputs more than 16 address bits, PSEN is actually the read signal.

This pin is connected to the PLDs. Therefore, these signals can be used in decode and other logic equations.

CNTL2 40 I This pin can be used to input the PSEN (Program Select

Enable) signal from any MCU that uses this signal for code exclusively. If your MCU does not output a Program Select Enable signal, this port can be used as a generic input. This port is connected to the PLD as input.

Reset 39 I Active low input. Resets I/O Ports, PLD Micro⇔Cells, some of

the configuration registers and JTAG registers. Must be active at power up. Reset also aborts the Flash programming/erase cycle that is in progress.

PSD835G2 PSD8XX Family

Pin*

(TQFP

Pin Name Pkg.) Type Description

PA0-PA7 51-58 I/O Port A, PA0-7. This port is pin configurable and has multiple

CMOS functions:

or Open 1. MCU I/O — standard output or input port

Drain 2. CPLD Micro⇔Cell (MCell A0-7) output.

3. Latched, transparent or registered PLD input.

PB0-PB7 61-68 I/O Port B, PB0-7. This port is pin configurable and has multiple

CMOS functions:

or Open 1. MCU I/O — standard output or input port.

Drain 2. CPLD Micro⇔Cell (MCell B0-7) output.

3. Latched, transparent or registered PLD input.

PC0-PC7 41-48 I/O Port C, PC0-7. This port is pin configurable and has multiple

CMOS functions:

or Slew 1. MCU I/O — standard output or input port.

Rate 2. External chip select (ECS0-7) output.

3. Latched, transparent or registered PLD input.

PD0 79 I/O Port D pin PD0 can be configured as:

CMOS 1. ALE or AS input — latches addresses on ADIO0-15 pins

or Open 2. AS input — latches addresses on ADIO0-15 pins on the

Drain rising edge.

3. Input to the PLD.

4. Transparent PLD input.

PD1 80 I/O Port D pin PD1 can be configured as:

CMOS 1. MCU I/O

or Open 2. Input to the PLD.

Drain 3. CLKIN clock input — clock input to the CPLD

Micro⇔Cells, the APD power down counter and CPLD AND Array.

PD2 1 I/O Port D pin PD2 can be configured as:

CMOS 1. MCU I/O

or Open 2. Input to the PLD.

Drain 3. CSI input — chip select input. When low, the CSI enables

the internal PSD memories and I/O. When high, the internal memories are disabled to conserve power. CSI trailing edge can get the part out of power-down mode.

PD3 2 I/O

Port D pin PD3 can be configured as:

CMOS

1. MCU I/O

or Open

2. Input to the PLD.

Drain

PE0 71 I/O Port E, PE0. This port is pin configurable and has multiple

CMOS functions:

or Open 1. MCU I/O — standard output or input port.

Drain 2. Latched address output.

3. TMS input for JTAG/ISP interface.

PE1 72 I/O Port E, PE1. This port is pin configurable and has multiple

CMOS functions:

or Open 1. MCU I/O — standard output or input port.

Drain 2. Latched address output.

3. TCK input for JTAG/ISP interface (Schmidt Trigger).

PE2 73 I/O Port E, PE2. This port is pin configurable and has multiple

CMOS functions:

or Open 1. MCU I/O — standard output or input port.

Drain 2. Latched address output.

3. TDI input for JTAG/ISP interface.

Table 5. PSD835G2 Pin Descriptions

(cont.)

PSD8XX Family PSD835G2

Pin*

(TQFP

Pin Name Pkg.) Type Description

PE3 74 I/O Port E, PE3. This port is pin configurable and has multiple

CMOS functions:

or Open 1. MCU I/O — standard output or input port.

Drain 2. Latched address output.

3. TDO output for JTAG/ISP interface.

PE4 75 I/O Port E, PE4. This port is pin configurable and has multiple

CMOS functions:

or Open 1. MCU I/O — standard output or input port.

Drain 2. Latched address output.

3. TSTAT output for the ISP interface.

4. Rdy/Bsy — for in-circuit Parallel Programming.

PE5 76 I/O Port E, PE5. This port is pin configurable and has multiple

CMOS functions:

or Open 1. MCU I/O — standard output or input port.

Drain 2. Latched address output.

3. TERR active low output for ISP interface.

PE6 77 I/O Port E, PE6. This port is pin configurable and has multiple

CMOS functions:

or Open 1. MCU I/O — standard output or input port.

Drain 2. Latched address output.

3. Vstby — SRAM standby voltage input for battery backup SRAM

PE7 78 I/O Port E, PE7. This port is pin configurable and has multiple

CMOS functions:

or Open 1. MCU I/O — standard output or input port.

Drain 2. Latched address output.

3. Vbaton — battery backup indicator output. Goes high when power is drawn from an external battery.

PF0-PF7 31-38 I/O Port F, PF0-7. This port is pin configurable and has multiple

CMOS functions:

or Open 1. MCU I/O — standard output or input port.

Drain 2. Input to the PLD.

3. Latched address outputs.

4. As address A0-3 inputs in 80C51XA mode

5. As data bus port (D0-7) in non-multiplexed bus configuration

PG0-PG7 21-28 I/O Port G, PG0-7. This port is pin configurable and has multiple

CMOS functions:

or Open 1. MCU I/O — standard output or input port.

Drain 2. Latched address outputs.

GND 8,30,

49,50,

9,29,

Table 5. PSD835G2 Pin Descriptions

(cont.)

PSD835G2 PSD8XX Family

Table 6 shows the offset addresses to the PSD835G2 registers relative to the CSIOP base address. The CSIOP space is the 256 bytes of address that is allocated by the user to the internal PSD835G2 registers. Table 6 provides brief descriptions of the registers in CSIOP space. For a more detailed description, refer to section 9.

7.0 PSD835G2 Register Description and Address Offset

Data In 00 01 10 11 30 40 41

Reads Port pin as input, MCU I/O input mode

Control 32 42 43

Selects mode between MCU I/O or Address Out

Stores data for output

Data Out 04 05 14 15 34 44 45 to Port pins, MCU I/O

output mode

Direction 06 07 16 17 36 46 47

Configures Port pin as input or output

Configures Port pins as either CMOS or Open

Drive Select 08 09 18 19 38 48 49 Drain on some pins, while

selecting high slew rate on other pins.

Input Micro⇔Cell 0A 0B 1A Reads Input Micro⇔Cells

Reads the status of the

Enable Out 0C 0D 1C 4C output enable to the I/O

Port driver

Read – reads output of Output Micro⇔Cells A Micro⇔Cells A

Write – loads Micro⇔cell

Flip-Flops

Read – reads output of Output Micro⇔Cells B Micro⇔Cells B

Write – loads Micro⇔cell

Flip-Flops

Mask

Blocks writing to the Micro⇔Cells A Output Micro⇔Cells A

Mask

Blocks writing to the Micro⇔Cells B Output Micro⇔Cells B

Flash Protection

C0 Read only – Flash Sector

Protection

Flash Boot

Read only – PSD Security Protection

C2 and Flash Boot Sector

Protection

JTAG Enable C7 Enables JTAG Port PMMR0 B0

Power Management

Places PSD memory VM E2

areas in Program and/or

Data space on an

individual basis. Memory_ID0 F0

Read only – Flash and

SRAM size Memory_ID1 F1

Read only – Boot type

and size

Table 6. Register Address Offset

PSD8XX Family PSD835G2

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Port Pin 7 Port Pin 6 Port Pin 5 Port Pin 4 Port Pin 3 Port Pin 2 Port Pin 1 Port Pin 0

Data In Registers – Port A, B, C, D, E, F and G

8.0 Register Bit Definition

All the registers in the PSD835G2 are included here for reference. Detail description of the registers are found in the Functional Block section of the Data Sheet.

Bit definitions:

Read only registers, read Port pin status when Port is in MCU I/O input Mode.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Port Pin 7 Port Pin 6 Port Pin 5 Port Pin 4 Port Pin 3 Port Pin 2 Port Pin 1 Port Pin 0

Data Out Registers – Port A, B, C, D, E, F and G

Bit definitions:

Latched data for output to Port pin when pin is configured in MCU I/O output mode.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Port Pin 7 Port Pin 6 Port Pin 5 Port Pin 4 Port Pin 3 Port Pin 2 Port Pin 1 Port Pin 0

Direction Registers – Port A, B, C, D, E, F and G

Bit definitions:

Set Register Bit to 0 = configure corresponding Port pin in Input mode (default). Set Register Bit to 1 = configure corresponding Port pin in Output mode.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Port Pin 7 Port Pin 6 Port Pin 5 Port Pin 4 Port Pin 3 Port Pin 2 Port Pin 1 Port Pin 0

Control Registers – Ports E, F and G

Bit definitions:

Set Register Bit to 0 = configure corresponding Port pin in MCU I/O mode (default). Set Register Bit to 1 = configure corresponding Port pin in Latched Address Out mode.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Port Pin 7 Port Pin 6 Port Pin 5 Port Pin 4 Port Pin 3 Port Pin 2 Port Pin 1 Port Pin 0

Drive Registers – Ports A, B, D, E, and G

Bit definitions:

Set Register Bit to 0 = configure corresponding Port pin in CMOS output driver (default). Set Register Bit to 1 = configure corresponding Port pin in Open Drain output driver.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Port Pin 7 Port Pin 6 Port Pin 5 Port Pin 4 Port Pin 3 Port Pin 2 Port Pin 1 Port Pin 0

Drive Registers – Ports C and F

Bit definitions:

Set Register Bit to 0 = configure corresponding Port pin as CMOS output driver (default). Set Register Bit to 1 = configure corresponding Port pin in Slew Rate mode.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Port Pin 7 Port Pin 6 Port Pin 5 Port Pin 4 Port Pin 3 Port Pin 2 Port Pin 1 Port Pin 0

Enable Out Registers – Ports A, B, C and F

Bit definitions: Read Only Registers

Register Bit <j> = 0 indicates Port pin driver is in tri-state mode (default). Register Bit <j> = 1 indicates Port pin driver is enabled.

PSD835G2 PSD8XX Family

8.0 Register Bit Definition

(cont.)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

IMcell7 IMcell6 IMcell5 IMcell4 IMcell3 IMcell2 IMcell1 IMcell0

Input Micro⇔Cells – Ports A, B and C

Bit definitions: Read Only Registers

Read Input Micro⇔Cell[7:0] status on Ports A, B and C.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Mcella7 Mcella6 Mcella5 Mcella4 Mcella3 Mcella2 Mcella1 Mcella0

Output Micro⇔Cells A Register

Bit definitions: Write Register: Load Micro⇔CellA[7:0] with 0 or 1. Read Register: Read Micro⇔CellA[7:0] output status.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Mcellb7 Mcellb6 Mcellb5 Mcellb4 Mcellb3 Mcellb2 Mcellb1 Mcellb0

Output Micro⇔Cells B Register

Bit definitions: Write Register: Load Micro⇔CellB[7:0] with 0 or 1. Read Register: Read Micro⇔CellB[7:0] output status.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Mcella7 Mcella6 Mcella5 Mcella4 Mcella3 Mcella2 Mcella1 Mcella0

Mask Micro⇔Cells A Register

Bit definitions:

Register Bit <j> to 0 = allow Micro⇔CellA<j> flip flop to be loaded by MCU (default). Register Bit <j> to 1 = does not allow Micro⇔CellA<j> flip flop to be loaded by MCU.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Mcellb7 Mcellb6 Mcellb5 Mcellb4 Mcellb3 Mcellb2 Mcellb1 Mcellb0

Mask Micro⇔Cells B Register

Bit definitions:

Register Bit <j> to 0 = allow Micro⇔CellB<j> flip flop to be loaded by MCU (default). Register Bit <j> to 1 = does not allow Micro⇔CellB<j> flip flop to be loaded by MCU.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Sec7_Prot Sec6_Prot Sec5_Prot Sec4_Prot Sec3_Prot Sec2_Prot Sec1_Prot Sec0_Prot

Flash Protection Register

Bit definitions: Read Only Register

Sec_Prot 1 = Flash Sector is write protected. Sec_Prot 0 = Flash Sector is not write protected.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Security_Bit

***

Sec3_Prot Sec2_Prot Sec1_Prot Sec0_Prot

Flash Boot Protection Register

Bit definitions:

Sec_Prot 1 = Boot Block Sector is write protected. Sec_Prot 0 = Boot Block Sector is not write protected.

Security_Bit 0 = Security Bit in device has not been set.

1 = Security Bit in device has been set.

PSD8XX Family PSD835G2

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

*******

JTAG_Enable

JTAG Enable Register

Bit definitions:

JTAG_Enable 1 = JTAG Port is Enabled.

0 = JTAG Port is Disabled.

8.0 Register Bit Definition

(cont.)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Pgr7 Pgr6 Pgr5 Pgr4 Pgr3 Pgr2 Pgr1 Pgr0

Page Register

Bit definitions:

Configure Page input to PLD. Default Pgr[7:0] = 00.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

PLD PLD PLD

APD

Mcells clk array-clk Turbo enable

PMMR0 Register

Bit definitions: (default is 0)

Bit 1 0 = Automatic Power Down (APD) is disabled.

1 = Automatic Power Down (APD) is enabled.

Bit 3 0 = PLD Turbo is on.

1 = PLD Turbo is off, saving power.

Bit 4 0 = CLKIN input to the PLD AND array is connected.

Every CLKIN change will power up the ZPLD when Turbo bit is off.

1 = CLKIN input to PLD AND array is disconnected, saving power.

Bit 5 0 = CLKIN input to the PLD Micro ⇔Cells is connected.

1 = CLKIN input to the PLD Micro ⇔Cells is disconnected, saving power.

*Not used bit should be set to zero.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

PLD PLD PLD PLD PLD

array WRh array Ale array Cntl2 array Cntl1 array Cntl0

PMMR1 Register

Bit definitions (default is 0):

Bit 0 0 = Address A[7:0] are connected into the PLD array.

1 = Address A[7:0] are blocked from the PLD array, saving power.

Note: in XA mode, A3-0 come from PF3-0 and A7-4 come from ADIO7-4.

Bit 2 0 = Cntl0 input to the PLD AND array is connected.

1 = Cntl0 input to the PLD AND array is disconnected, saving power.

Bit 3 0 = Cntl1 input to the PLD AND array is connected.

1 = Cntl1 input to the PLD AND array is disconnected, saving power.

Bit 4 0 = Cntl2 input to the PLD AND array is connected.

1 = Cntl2 input to the PLD AND array is disconnected, saving power.

Bit 5 0 = Ale input to the PLD AND array is connected.

1 = Ale input to the PLD AND array is disconnected, saving power.

Bit 6 0 = WRh/DBE input to the PLD AND array is connected.

1 = WRh/DBE input to the PLD AND array is disconnected, saving power.

*Not used bit should be set to zero.

PSD835G2 PSD8XX Family

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Periph-

FL_data Boot_data FL_code Boot_code SR_code

mode

VM Register

Bit definitions:

Bit 0 0 = PSEN can’t access SRAM in 80C51XA modes.

1 = PSEN can access SRAM in 80C51XA modes.

Bit 1 0 = PSEN can’t access Boot in 80C51XA modes.

1 = PSEN can access Boot in 80C51XA modes.

Bit 2 0 = PSEN can’t access main Flash in 80C51XA modes.

1 = PSEN can access main Flash in 80C51XA modes.

Bit 3 0 = RD can’t access Boot in 80C51XA modes.

1 = RD can access Boot in 80C51XA modes.

Bit 4 0 = RD can’t access main Flash in 80C51XA modes.

1 = RD can access main Flash in 80C51XA modes.

Bit 7 0 = Peripheral mode of Port F is disabled.

1 = Peripheral mode of Port F is enabled.

Note: Upon reset, Bit1-Bit4 are loaded to configurations selected by the user in PSDsoft. Bit 0 and Bit 7 are

always cleared by reset. Bit 0 to Bit 4 are active only when the device is configured in Philips 80C51XA mode.

* Not used bit should be set to zero

8.0 Register Bit Definition

(cont.)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

S_size 3 S_size 2 S_size 1 S_size 0 F_size 3 F_size 2 F_size 1 F_size 0

Memory_ID0 Register

Bit definitions:

F_size[3:0] = 4h, main Flash size is 2M bit. F_size[3:0] = 5h, main Flash size is 8M bit. S_size[3:0] = 0h, SRAM size is 0K bit. S_size[3:0] = 1h, SRAM size is 16K bit. S_size[3:0] = 3h, SRAM size is 64K bit.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

B_type 1 B_type 0 B_size 3 B_size 2 B_size 1 B_size 0

Memory_ID1 Register

Bit definitions:

B_size[3:0] = 0h, Boot block size is 0K bit. B_size[3:0] = 2h, Boot block size is 256K bit. B_type[1:0] = 0h, Boot block is Flash memory.

*Not used bit should be set to zero.

PSD8XX Family PSD835G2

9.0 The PSD835G2 Functional Blocks

As shown in Figure 1, the PSD835G2 consists of six major types of functional blocks:

❏ Memory Blocks ❏ PLD Blocks ❏ Bus Interface ❏ I/O Ports ❏ Power Management Unit ❏ JTAG-ISP Interface

The functions of each block are described in the following sections. Many of the blocks perform multiple functions, and are user configurable.

9.1 Memory Blocks

The PSD835G2 has the following memory blocks:

• The main Flash memory

• Secondary Flash memory

• SRAM.

The memory select signals for these blocks originate from the Decode PLD (DPLD) and are user-defined in PSDsoft.

Table 7 summarizes which versions of the PSD835G2 contain which memory blocks.

Main Flash Secondary Flash

Device Flash Size Sector Size Block Size Sector Size SRAM

PSD835G2 512KB 64KB 32KB 8KB 8KB

Table 7. Memory Blocks

9.1.1 Main Flash and Secondary Flash Memory Description

The main Flash memory block is divided evenly into eight sectors. The secondary Flash memory is divided into four sectors of eight Kbytes each. Each sector of either memory can be separately protected from program and erase operations.

Flash memory may be erased on a sector-by-sector basis and programmed word-by-word. Flash sector erasure may be suspended while data is read from other sectors of memory and then resumed after reading.

During a program or erase of Flash, the status can be output on the Rdy/Bsy pin of Port PE4. This pin is set up using PSDsoft.

9.1.1.1 Memory Block Selects

The decode PLD in the PSD835G2 generates the chip selects for all the internal memory blocks (refer to the PLD section). Each of the eight Flash memory sectors have a Flash Select signal (FS0 -FS7) which can contain up to three product terms. Each of the four Secondary Flash memory sectors have a Select signal (CSBOOT0-3) which can contain up to three product terms. Having three product terms for each sector select signal allows a given sector to be mapped in different areas of system memory. When using a microcontroller (80C51) with separate Program and Data space, these flexible select signals allow dynamic re-mapping of sectors from one space to the other before and after IAP.

PSD835G2 PSD8XX Family

9.1.1.2 Upper and Lower Block IN MAIN FLASH SECTOR

The PSD835G2’s main Flash has eight 64K bytes sector. The 64K byte sector size may cause some difficulty in code mapping for an 8-bit MCU with only 64K byte address space. To resolve this mapping issue, the PSD835G2 provides additional logic (Figure 3) for the user to split the 8 sectors such that each sector has a lower and upper 32K byte block, and the two blocks can reside in different pages but in the same address range.

If your design works with 64KB sectors, you don’t need to configure this logic. If the design requires 32KB blocks in each sector, you need to define a “FA15” PLD equation in PSDsoft as the A15 address input to the main Flash module. FA15 consists of 3 product terms and will control whether the MCU is accessing the lower or upper 32KB in the selected sector. Below is an example for Flash sector chip select FS0. A typical equation is FA15 = pgr4 of the Page Register. When pgr4 is 0 (page 00), the lower 32KB is selected. When pgr4 is switched to 1 by the user, the upper 32KB is selected. PSDsoft will automatically generate the PLD equations shown, based on your point and click selections.

page = [pgr7...pgr0]; “Page Register output

“Sector Chip Select Equation

FS0 = ((0000h <= address <= 7FFFh) & page = 00h) # “select first 32KB block

((0000h <= address <= 7FFFh) & page = 10h); “select second 32KB block

FA15 = pgr4; “as address A15 input to the main Flash

If no FA15 equation is defined in PSDsoft, the A15 that comes from the MCU address bus will be routed as input to the main Flash instead of FA15. The FA15 equation has no impact in the Sector Erase operation. Note: FA15 affects all eight sectors of the main Flash simultaneously, you cannot direct FA15 to a particular Flash sector only.

9.1.1.3 The Ready/Busy Pin (PE4)

Pin PE4 can be used to output the Ready/Busy status of the PSD835G2. The output on the pin will be a ‘0’ (Busy) when Flash memory blocks are being written to, or when the Flash memory block is being erased. The output will be a ‘1’ (Ready) when no write or erase operation is in progress.

The PSD835G2 Functional Blocks

(cont.)

DPLD

ARRAY

FA15

A15

* Set by PSDsoft

FLASH CHIP SELECTS FS0-7

MUX

NVM CONTROL BIT

MAIN

FLASH

SECTOR

ADDR A15

A [14:0]

Figure 3. Selecting the Upper or Lower Block in a Main Flash Sector

9.1.1.4 Memory Operation

The main Flash and secondary Flash memories are addressed through the microcontroller interface on the PSD835G2 device. The microcontroller can access these memories in one of two ways:

❏ The microcontroller can execute a typical bus write or read operation just as it would

if accessing a RAM or ROM device using standard bus cycles.

❏ The microcontroller can execute a specific instruction that consists of several write

and read operations. This involves writing specific data patterns to special addresses within the Flash to invoke an embedded algorithm. These instructions are summarized in Table 8.

Typically, Flash memory can be read by the microcontroller using read operations, just as it would read a ROM device. However, Flash memory can only be erased and programmed with specific instructions. For example, the microcontroller cannot write a single byte directly to Flash memory as one would write a byte to RAM. To program a byte into Flash memory, the microcontroller must execute a program instruction sequence, then test the status of the programming event. This status test is achieved by a read operation or polling the Rdy/Busy pin (PE4).

The Flash memory can also be read by using special instructions to retrieve particular Flash device information (sector protect status and ID).

9.1.1.4.1 Instructions

An instruction is defined as a sequence of specific operations. Each received byte is sequentially decoded by the PSD and not executed as a standard write operation. The instruction is executed when the correct number of bytes are properly received and the time between two consecutive bytes is shorter than the time-out value. Some instructions are structured to include read operations after the initial write operations.

The sequencing of any instruction must be followed exactly. Any invalid combination of instruction bytes or time-out between two consecutive bytes while addressing Flash memory will reset the device logic into a read array mode (Flash memory reads like a ROM device).

The PSD835G2 main Flash and secondary Flash support these instructions (see Table 8):

❏ Erase memory by chip or sector ❏ Suspend or resume sector erase ❏ Program a byte ❏ Reset to read array mode ❏ Read Main Flash Identifier value ❏ Read sector protection status ❏ Bypass Instruction

These instructions are detailed in Table 8. For efficient decoding of the instructions, the first two bytes of an instruction are the coded cycles and are followed by a command byte or confirmation byte. The coded cycles consist of writing the data AAh to address X555h during the first cycle and data 55h to address XAAAh during the second cycle (unless the Bypass Instruction feature is used. See 9.1.1.7). Address lines A15-A12 are don’t care during the instruction write cycles. However, the appropriate sector select signal (FSi or CSBOOTi) must be selected.

The main Flash and the secondary Flash Block have the same set of instructions (except Read main Flash ID). The chip selects of the Flash memory will determine which Flash will receive and execute the instruction. The main Flash is selected if any one of the FS0-7 is active, and the secondary Flash Block is selected if any one of the CSBOOT0-3 is active.

The PSD835G2 Functional Blocks

(cont.)

PSD8XX Family PSD835G2

PSD835G2 PSD8XX Family

The PSD835G2 Functional Blocks

(cont.)

FS0-7

Instruction CSBOOT0-3 Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle5 Cycle 6 Cycle 7

Read (Note 5) 1 “Read”

RA RD

Read Main Flash ID 1 AAh 55h 90h “Read” (Notes 6,13) @555h @AAAh @555h ID

@x01h

Read Sector Protection 1 AAh 55h 90h “Read” (Notes 6,8,13) @555h @AAAh @555h 00h or 01h

@x02h

Program a Flash Byte 1 AAh 55h A0h PD@PA

@555h @AAAh @555h

Erase One Flash Sector 1 AAh 55h 80h AAh 55h 30h 30h

@555h @AAAh @555h @555h @AAAh @SA @next SA

(Note 7)

Erase Flash Block 1 AAh 55h 80h AAh 55h 10h (Bulk Erase) @555h @AAAh @555h @555h @AAAh @555h

Suspend Sector Erase 1 B0h (Note 11) @xxxh

Resume Sector Erase 1 30h (Note 12) @xxxh

Reset (Note 6) 1 F0 @ any

address

Unlock Bypass 1 AAh 55h 20h

@555h @AAAh @555h

Unlock Bypass Program 1 A0h PD@PA (Note 9) @xxxh

Unlock Bypass Reset 1 90h 00h (Note 10) @xxxh @xxxh

Table 8. Instructions

X = Don’t Care. RA = Address of the memory location to be read. RD = Data read from location RA during read operation. PA = Address of the memory location to be programmed. Addresses are latched on the falling edge of the WR#

(CNTL0) pulse. PD = Data to be programmed at location PA. Data is latched o the rising edge of WR# (CNTL0) pulse. SA = Address of the sector to be erased or verified. The chip select (FS0-7 or CSBOOT0-3) of the sector to be

erased must be active (high).

NOTES:

1. All bus cycles are write bus cycle except the ones with the “read” label.

2. All values are in hexadecimal.

3. FS0-7 and CSBOOT0-3 are active high and are defined in PSDsoft.

4. Only Address bits A11-A0 are used in Instruction decoding. A15-12 (or A16-A12) are don’t care.

5. No unlock or command cycles required when device is in read mode.

6. The Reset command is required to return to the read mode after reading the Flash ID, Sector Protect status

or if DQ5 (error flag) goes high.

7. Additional sectors to be erased must be entered within 80µs.

8. The data is 00h for an unprotected sector and 01h for a protected sector. In the fourth cycle, the sector chip

select is active and (A1 = 1, A0 = 0).

9. The Unlock Bypass command is required prior to the Unlock Bypass Program command.

10. The Unlock Bypass Reset command is required to return to reading array data when the device is in the

Unlock Bypass mode.

11. The system may read and program functions in non-erasing sectors, read the Flash ID or read the Sector

Protect status, when in the Erase Suspend mode. The erase Suspend command is valid only during a sector erase operation.

12. The Erase Resume command is valid only during the Erase Suspend mode.

13. The MCU cannot invoke these instructions while executing code from the same Flash memory for which the

instruction is intended. The MCU must fetch, for example, codes from the secondary block when reading the Sector Protection Status of the main Flash.

PSD8XX Family PSD835G2

The PSD835G2 Functional Blocks

(cont.)

9.1.1.5 Power-Up Condition

The PSD835G2 internal logic is reset upon power-up to the read array mode. The FSi and CSBOOTi select signals, along with the write strobe signal, must be in the false state during power-up for maximum security of the data contents and to remove the possibility of data being written on the first edge of a write strobe signal. Any write cycle initiation is locked when VCCis below VLKO.

9.1.1.6 Read

Under typical conditions, the microcontroller may read the Flash, or secondary Flash memories using read operations just as it would a ROM or RAM device. Alternately, the microcontoller may use read operations to obtain status information about a program or erase operation in progress. Lastly, the microcontroller may use instructions to read special data from these memories. The following sections describe these read functions.

9.1.1.6.1 Read the Contents of Memory

Main Flash and secodary Flash memories are placed in the read array mode after power-up, chip reset, or a Reset Flash instruction (see Table 8). The microcontroller can read the memory contents of main Flash or secondary Flash by using read operations any time the read operation is not part of an instruction sequence.

9.1.1.6.2 Read the Main Flash Memory Identifier

The main Flash memory identifier is read with an instruction composed of 4 operations: 3 specific write operations and a read operation (see Table 8). The PSD835G2 main Flash memory ID is E8h.

9.1.1.6.3 Read the Flash Memory Sector Protection Status

The Flash memory sector protection status is read with an instruction composed of 4 operations: 3 specific write operations and a read operation (see Table 8). The read operation will produce 01h if the Flash sector is protected, or 00h if the sector is not protected.

The sector protection status for all NVM blocks (main Flash or secondary Flash) can also be read by the microcontroller accessing the Flash Protection and Flash Boot Protection registers in PSD I/O space. See section 9.1.1.9.1 for register definitions.

9.1.1.6.4 Read the Erase/Program Status Bits

The PSD835G2 provides several status bits to be used by the microcontroller to confirm the completion of an erase or programming instruction of Flash memory. These status bits minimize the time that the microcontroller spends performing these tasks and are defined in Table 9. The status bits can be read as many times as needed.

FSi/

CSBOOTi DQ7 DQ6 DQ5 DQ4 DQ3 DQ2 DQ1 DQ0

Data Toggle Error

Erase

Flash V

Polling Flag Flag

X Time- X X X

out

Table 9. Status Bits

NOTES: 1. X = Not guaranteed value, can be read either 1 or 0.

2. DQ7-DQ0 represent the Data Bus bits, D7-D0.

3. FSi/CSBOOTi are active high.

For Flash memory, the microcontroller can perform a read operation to obtain these status bits while an erase or program instruction is being executed by the embedded algorithm. See section 9.1.1.7 for details.

PSD835G2 PSD8XX Family

The PSD835G2 Functional Blocks

(cont.)

9.1.1.6.5 Data Polling Flag DQ7

When Erasing or Programming the Flash memory bit DQ7 outputs the complement of the bit being entered for Programming/Writing on DQ7. Once the Program instruction or the Write operation is completed, the true logic value is read on DQ7 (in a Read operation). Flash memory specific features:

❏ Data Polling is effective after the fourth Write pulse (for programming) or after the

sixth Write pulse (for Erase). It must be performed at the address being programmed or at an address within the Flash sector being erased.

❏ During an Erase instruction, DQ7 outputs a ‘0’. After completion of the instruction,

DQ7 will output the last bit programmed (it is a ‘1’ after erasing).

❏ If the location to be programmed is in a protected Flash sector, the instruction is

ignored.

❏ If all the Flash sectors to be erased are protected, DQ7 will be set to ‘0’ for

about 100 µs, and then return to the previous addressed location. No erasure will be performed.

9.1.1.6.6 Toggle Flag DQ6

The PSD835G2 offers another way for determining when the Flash memory Program instruction is completed. During the internal Write operation and when either the FSi or CSBOOTi is true, the DQ6 will toggle from ‘0’ to ‘1’ and ‘1’ to ‘0’ on subsequent attempts to read any byte of the memory.

When the internal cycle is complete, the toggling will stop and the data read on the Data Bus D0-7 is the addressed memory location. The device is now accessible for a new Read or Write operation. The operation is finished when two successive reads yield the same output data. Flash memory specific features:

❏ The Toggle bit is effective after the fourth Write pulse (for programming) or after the

sixth Write pulse (for Erase).

❏ If the location to be programmed belongs to a protected Flash sector, the instruction

is ignored.

❏ If all the Flash sectors selected for erasure are protected, DQ6 will toggle to ‘0’ for

about 100 µs and then return to the previous addressed location.

9.1.1.6.7 Error Flag DQ5

During a correct Program or Erase, the Error bit will set to ‘0’. This bit is set to ‘1’ when there is a failure during Flash programming, Sector erase, or Bulk Erase.

In the case of Flash programming, the Error Bit indicates the attempt to program a Flash bit(s) from the programmed state (0) to the erased state (1), which is not a valid operation. The Error bit may also indicate a timeout condition while attempting to program a byte.

In case of an error in Flash sector erase or byte program, the Flash sector in which the error occurred or to which the programmed location belongs must no longer be used. Other Flash sectors may still be used. The Error bit resets after the Reset instruction.

9.1.1.6.8 Erase Time-out Flag DQ3

The Erase Timer bit reflects the time-out period allowed between two consecutive Sector Erase instructions. The Erase timer bit is set to ‘0’ after a Sector Erase instruction for a time period of 100 µs + 20% unless an additional Sector Erase instruction is decoded. After this time period or when the additional Sector Erase instruction is decoded, DQ3 is set to ‘1’.

PSD8XX Family PSD835G2

9.1.1.7 Programming Flash Memory

Flash memory must be erased prior to being programmed. The MCU may erase Flash memory all at once or by-sector. Flash memory sector erases to all logic ones (FF hex), and its bits are programmed to logic zeros. Although erasing Flash memory occurs on a sector basis, programming Flash memory occurs on a word basis.

The PSD835G2 main Flash and secondary Flash memories require the MCU to send an instruction to program a word or perform an erase function (see Table 8).

Once the MCU issues a Flash memory program or erase instruction, it must check for the status of completion. The embedded algorithms that are invoked inside the PSD835G2 support several means to provide status to the MCU. Status may be checked using any of three methods: Data Polling, Data Toggle, or the Ready/Busy output pin.

9.1.1.7.1 Data Polling

Polling on DQ7 is a method of checking whether a Program or Erase instruction is in progress or has completed. Figure 4 shows the Data Polling algorithm.

When the MCU issues a programming instruction, the embedded algorithm within the PSD835G2 begins. The MCU then reads the location of the word to be programmed in Flash to check status. Data bit DQ7 of this location becomes the compliment of data bit 7of the original data word to be programmed. The MCU continues to poll this location, comparing DQ7 and monitoring the Error bit on DQ5. When the DQ7 matches data bit 7 of the original data, and the Error bit at DQ5 remains ‘0’, then the embedded algorithm is complete. If the Error bit at DQ5 is ‘1’, the MCU should test DQ7 again since DQ7 may have changed simultaneously with DQ5 (see Figure 4).

The Error bit at DQ5 will be set if either an internal timeout occurred while the embedded algorithm attempted to program the location or if the MCU attempted to program a ‘1’ to a bit that was not erased (not erased is logic ‘0’).

It is suggested (as with all Flash memories) to read the location again after the embedded programming algorithm has completed to compare the word that was written to Flash with the word that was intended to be written.

When using the Data Polling method after an erase instruction, Figure 4 still applies. However, DQ7 will be ‘0’ until the erase operation is complete. A ‘1’ on DQ5 will indicate a timeout failure of the erase operation, a ‘0’ indicates no error. The MCU can read any location within the sector being erased to get DQ7 and DQ5.

PSDsoft generates ANSI C code functions which implement these Data Polling algorithms.

The PSD835G2 Functional Blocks

(cont.)

PSD835G2 PSD8XX Family

Figure 4. Data Polling Flow Chart

START

READ DQ5 & DQ7

at VALID ADDRESS

YES

DQ7

DATA7

DQ5

DQ7

DATA

READ DQ7

FAIL

Program/Erase

Operation Failed

Issue Reset Instruction

PASS

Program/Erase

Operation is

Completed

The PSD835G2 Functional Blocks

(cont.)

9.1.1.7.2 Data Toggle

Checking the Data Toggle bit on DQ6 is a method of determining whether a Program or Erase instruction is in progress or has completed. Figure 5 shows the Data Toggle algorithm.

When the MCU issues a programming instruction, the embedded algorithm within the PSD835G2 begins. The MCU then reads the location to be programmed in Flash to check status. Data bit DQ6 of this location will toggle each time the MCU reads this location until the embedded algorithm is complete. The MCU continues to read this location, checking DQ6 and monitoring the Error bit on DQ5. When DQ6 stops toggling (two consecutive reads yield the same value), and the Error bit on DQ5 remains ‘0’, then the embedded algorithm is complete. If the Error bit on DQ5 is ‘1’, the MCU should test DQ6 again, since DQ6 may have changed simultaneously with DQ5 (see Figure 5).

The Error bit at DQ5 will be set if either an internal timeout occurred while the embedded algorithm attempted to program, or if the MCU attempted to program a ‘1’ to a bit that was not erased (not erased is logic ‘0’).

PSD8XX Family PSD835G2

9.1.1.7.2 Data Toggle (cont.)

When using the Data Toggle method after an erase instructin, Figure 5 still applies. DQ6 will toggle until the erase operation is complete. A ‘1’ on DQ5 will indicate a timeout failure of the erase operation, a ‘0’ indicates no error. The MCU can read any even location within the sector being erased to get DQ6 and DQ5.

PSDsoft generates ANSI C code functions which implement these Data Toggling algorithms.

The PSD835G2 Functional Blocks

(cont.)

Figure 5. Data Toggle Flow Chart

START

READ

DQ5 & DQ6

YES

DQ6

TOGGLE

DQ5

DQ6

TOGGLE

READ DQ6

FAIL

Program/Erase

Operation Failed

Issue Reset Instruction

PASS

Program/Erase

Operation is

Completed

PSD835G2 PSD8XX Family

The PSD835G2 Functional Blocks

(cont.)

9.1.1.8 Unlock Bypass Instruction

The unlock bypass feature allows the system to program words to the flash memories faster than using the standard program instruction. The unlock bypass instruction is initiated by first writing two unlock cycles. This is followed by a third write cycle containing the unlock bypass command, 20h (see Table 8). The flash memory then enters the unlock bypass mode. A two-cycle Unlock Bypass Program instruction is all that is required to program in this mode. The first cycle in this instruction contains the unlock bypass programm command, A0h; the second cycle contains the program address and data. Additional data is programmed in the same manner. This mode dispenses with the initial two unlock cycles required in the standard program instruction, resulting in faster total programming time. During the unlock bypass mode, only the Unlock Bypass Program and Unlock Bypass Reset instructions are valid. To exit the unlock bypass mode, the system must issue the two-cycle unlock bypass reset instruction. The first cycle must contain the data 90h; the second cycle the data 00h. Addresses are don’t care for both cycles. The Flash memory then returns to reading array data mode.

9.1.1.9 Erasing Flash Memory

9.1.1.9.1. Flash Bulk Erase Instruction

The Flash Bulk Erase instruction uses six write operations followed by a Read operation of the status register, as described in Table 8. If any byte of the Bulk Erase instruction is wrong, the Bulk Erase instruction aborts and the device is reset to the Read Flash memory status.

During a Bulk Erase, the memory status may be checked by reading status bits DQ5, DQ6, and DQ7, as detailed in section 9.1.1.7. The Error bit (DQ5) returns a ‘1’ if there has been an Erase Failure (maximum number of erase cycles have been executed).

It is not necessary to program the array with 00h because the PSD835G2 will automatically do this before erasing to 0FFh.

During execution of the Bulk Erase instruction, the Flash memory will not accept any instructions.

9.1.1.9.2 Flash Sector Erase Instruction

The Sector Erase instruction uses six write operations, as described in Table 8. Additional Flash Sector Erase confirm commands and Flash sector addresses can be written subsequently to erase other Flash sectors in parallel, without further coded cycles, if the additional instruction is transmitted in a shorter time than the timeout period of about 100 µs. The input of a new Sector Erase instruction will restart the time-out period.

The status of the internal timer can be monitored through the level of DQ3 (Erase time-out bit). If DQ3 is ‘0’, the Sector Erase instruction has been received and the timeout is counting. If DQ3 is ‘1’, the timeout has expired and the PSD835G2 is busy erasing the Flash sector(s). Before and during Erase timeout, any instruction other than Erase suspend and Erase Resume will abort the instruction and reset the device to Read Array mode. It is not necessary to program the Flash sector with 00h as the PSD835G2 will do this automatically before erasing.

During a Sector Erase, the memory status may be checked by reading status bits DQ5, DQ6, and DQ7, as detailed in section 9.1.1.7.

During execution of the erase instruction, the Flash block logic accepts only Reset and Erase Suspend instructions. Erasure of one Flash sector may be suspended, in order to read data from another Flash sector, and then resumed.

PSD8XX Family PSD835G2

The PSD835G2 Functional Blocks

(cont.)

9.1.1.9.3 Flash Erase Suspend Instruction

When a Flash Sector Erase operation is in progress, the Erase Suspend instruction will suspend the operation by writing 0B0h to any even address when an appropriate Chip Select (FSi or CSBOOTi) is true. (See Table 8). This allows reading of data from another Flash sector after the Erase operation has been suspended. Erase suspend is accepted only during the Flash Sector Erase instruction execution and defaults to read array mode. An Erase Suspend instruction executed during an Erase timeout will, in addition to suspending the erase, terminate the time out.

The Toggle Bit DQ6 stops toggling when the PSD835G2 internal logic is suspended. The toggle Bit status must be monitored at an address within the Flash sector being erased. The Toggle Bit will stop toggling between 0.1 µs and 15 µs after the Erase Suspend instruction has been executed. The PSD835G2 will then automatically be set to Read Flash Block Memory Array mode.

If an Erase Suspend instruction was executed, the following rules apply:

• Attempting to read from a Flash sector that was being erased will output invalid data.

• Reading from a Flash sector that was not being erased is valid.

• The Flash memory cannot be programmed, and will only respond to Erase Resume

and Reset instructions (read is an operation and is OK).

• If a Reset instruction is received, data in the Flash sector that was being erased will

be invalid.

9.1.1.9.4 Flash Erase Resume Instruction

If an Erase Suspend instruction was previously executed, the erase operation may be resumed by this instruction. The Erase Resume instruction consists of writing 030h to any even address while an appropriate Chip Select (FSi or CSBOOTi) is true. (See Table 8.)

9.1.1.10 Specific Features

9.1.1.10.1 Main Flash and Secondary Flash Sector Protect

Each sector of main Flash and secondary Flash memory can be separately protected against Program and Erase functions. Sector Protection provides additional data security because it disables all program or erase operations. This mode can be activated (or deactivated) through the JTAG-ISP Port or a Device Programmer.

Sector protection can be selected for each sector using the PSDsoft program. This will automatically protect selected sectors when the device is programmed through the JTAG Port or a Device Programmer. Flash sectors can be unprotected to allow updating of their contents using the JTAG Port or a Device Programmer. The microcontroller can read (but cannot change) the sector protection bits.

Any attempt to program or erase a protected Flash sector will be ignored by the device. The Verify operation will result in a read of the protected data. This allows a guarantee of the retention of the Protection status.

The sector protection status can either be read by the MCU through the Flash protection and secondary Flash protection registers (CSIOP) or use the read sector protection instruction (Table 8).

PSD835G2 PSD8XX Family

The PSD835G2 Functional Blocks

(cont.)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Sec7_Prot Sec6_Prot Sec5_Prot Sec4_Prot Sec3_Prot Sec2_Prot Sec1_Prot Sec0_Prot

Flash Protection Register

9.1.1.10.2 Reset Instruction

The Reset instruction consists of one write cycle (see Table 8). It can also be optionally preceded by the standard two write decoding cycles (writing AAh to AAAh and 55h to 554h).

The Reset instruction must be executed after:

1. Reading the Flash Protection status or Flash ID using the Flash instruction.

2. When an error condition occurs (DQ5 goes high) during a Flash programming or erase cycle.

The Reset instruction will reset the Flash to normal Read Mode immediately. However, if there is an error condition (DQ5 goes high), the Flash memory will return to the Read Mode in 25 µSeconds after the Reset instruction is issued.

The Reset instruction is ignored when it is issued during a Flash programming or Bulk Erase cycle. The Reset instruction will abort the on going sector erase cycle and return the Flash memory to normal Read Mode in 25 µSeconds.

9.1.1.10.3 Reset Pin Input

The reset pulse input from the pin will abort any operation in progress and reset the Flash memory to Read Mode. When the reset occurs during a programming or erase cycle, the Flash memory will take up to 25 µSeconds to return to Read Mode. It is recommended that the reset pulse (except power on reset, see Reset Section) be at least 25 µSeconds such that the Flash memory will always be ready for the MCU to fetch the boot code after reset is over.

Bit Definitions:

Sec_Prot 1 = Main Flash Sector is write protected. Sec_Prot 0 = Main Flash Sector is not write protected.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Security_

***

Sec3_Prot Sec2_Prot Sec1_Prot Sec0_Prot

Bit

Flash Boot Protection Register

Bit Definitions:

Sec_Prot 1 = Flash Boot Sector is write protected. Sec_Prot 0 = Flash Boot Sector is not write protected.

Security_Bit 0 = Security Bit in device has not been set.

1 = Security Bit in device has been set.

Table 10. Sector Protection/Security Bit Definition

*: Not used.

PSD8XX Family PSD835G2

The PSD835G2 Functional Blocks

(cont.)

9.1.2 SRAM

The SRAM is enabled when RS0 —the SRAM chip select output from the DPLD —is high. RS0 can contain up to three product terms, allowing flexible memory mapping.

The SRAM can be backed up using an external battery. The external battery should be connected to the Vstby pin (PE6). If you have an external battery connected to the PSD835G2, the contents of the SRAM will be retained in the event of a power loss. The contents of the SRAM will be retained so long as the battery voltage remains at 2V or greater. If the supply voltage falls below the battery voltage, an internal power switchover to the battery occurs.

Pin PE7 can be configured as an output that indicates when power is being drawn from the external battery. This Vbaton signal will be high with the supply voltage falls below the battery voltage and the battery on PE6 is supplying power to the internal SRAM.

The chip select signal (RS0) for the SRAM, Vstby, and Vbaton are all configured using PSDsoft.

9.1.3 Memory Select Signals

The main Flash (FSi), secondary Flash (CSBOOTi), and SRAM (RS0) memory select signals are all outputs of the DPLD. They are defined using PSDsoft. The following rules apply to the equations for the internal chip select signals:

1. Main Flash memory and secondary Flash memory sector select signals must not be larger than the physical sector size.

2. Any main Flash memory sector must not be mapped in the same memory space as another Main Flash sector.

3. A secondary Flash memory sector must not be mapped in the same memory space as another Flash Boot sector.

4. SRAM and I/O spaces must not overlap.

5. A secondary Flash memory sector may overlap a main Flash memory sector. In case of overlap, priority will be given to the Flash Boot sector.

6. SRAM and I/O spaces may overlap any other memory sector. Priority will be given to the SRAM and I/O.

Example

FS0 is valid when the address is in the range of 8000h to BFFFh, CSBOOT0 is valid from 8000h to 9FFFh, and RS0 is valid from 8000h to 87FFh. Any address in the range of RS0 will always access the SRAM. Any address in the range of CSBOOT0 greater than 87FFh (and less than 9FFFh) will automatically address Boot memory segment 0. Any address greater than 9FFFh will access the Flash memory segment 0. You can see that half of the Flash memory segment 0 and one-fourth of Boot segment 0 can not be accessed in this example. Also note that an equation that defined FS1 to anywhere in the range of 8000h to BFFFh would not be valid.

Figure 6 shows the priority levels for all memory components. Any component on a higher level can overlap and has priority over any component on a lower level. Components on the same level must not overlap. Level one has the highest priority and level 3 has the lowest.

PSD835G2 PSD8XX Family

The PSD835G2 Functional Blocks

(cont.)

Level 1

SRAM, I/O, or Peripheral I/O

Level 2

Secondary Flash Memory

Highest Priority

Lowest Priority

Level 3

Main Flash Memory

Figure 6. Priority Level of Memory and I/O Components

9.1.3.1. Memory Select Configuration for MCUs with Separate Program and Data Spaces

The 80C51 and compatible family of microcontrollers, can be configured to have separate address spaces for code memory (selected using PSEN) and data memory (selected using RD). Any of the memories within the PSD835G2 can reside in either space or both spaces. This is controlled through manipulation of the VM register that resides in the PSD’s CSIOP space.

The VM register is set using PSDsoft to have an initial value. It can subsequently be changed by the microcontroller so that memory mapping can be changed on-the-fly. For example, you may wish to have SRAM and main Flash in Data Space at boot, and secondary Flash memory in Program Space at boot, and later swap main and secondary Flash memory. This is easily done with the VM register by using PSDsoft to configure it for boot up and having the microcontroller change it when desired.

Table 11 describes the VM Register.

Bit 7 Bit 6* Bit 5* Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PIO_EN FL_Data Boot_Data FL_Code Boot_Code SRAM_Code

0 = disable

0 = RD 0 = RD 0 = PSEN 0 = PSEN 0 = PSEN

PIO mode can’t can’t can’t can’t can’t

access access access access access Flash Boot Flash Flash Boot Flash SRAM

1= enable

1 = RD 1 = RD 1 = PSEN 1 = PSEN 1 = PSEN

PIO mode access access access access access

Flash Boot Flash Flash Boot Flash SRAM

Table 11. VM Register

NOTE: Bits 6-5 are not used.

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