Integrated 802.11n MAC/BBP and 2.4 GHz RF/FEM Router-on-a-Chip
PGMT7620_V.1.0_040503
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MT7620 PROGRAMMING GUIDE
Integrated 802.11n MAC/BBP and 2.4 GHz RF/FEM Router-on-a-Chip
MIPS 24KEc
64 KB I-Cache
32 KB D-
Cache
(580 MHz)
OCP Bridge
OCP
_IF
Arbiter
DRAM
Controller
RBUS (SYS_CLK)
SPI
NFC
PBUS
GDMA
RJ45 x5
Switch
(4FE + 2GE)
5-Port EPHY
RGMII
TMII/MII
x2
PCIe 1.1
PHY
Single-Port
USB 2.0 PHY
Host/
Device
PCIe x1
UART
GPIO
PCM x4
I2S
I2C
I2S
PBUS
INTC
I2C
GPIO
/LED
SPI
NAND
UART
To CPU
interrupt
s
16-Bit
SDR/DDR1/DDR2
EJTAG
WLAN
11n 2x2
2.4 GHz
Timer
PCM
SDHC
SD
MT7620 Overview
The MT7620 SoC includes a high performance 580 MHz MIPS24KEc CPU core and USB host controller/PHY,
which is designed to enable a multitude of high performance, cost-effective IEEE 802.11n applications with a
MediaTek (Ralink) client card.
Functional Block Diagram
Figure 1-1 MT7620 Block Diagram
There are several masters (MIPS 24KEc, USB , PCI Express) in the MT7620 SoC on a high performance, low
latency Rbus, (Ralink Bus). In addition, the MT7620 SoC supports lower speed peripherals such as UART, GPIO,
and SPI via a low speed peripheral bus (Pbus). The SDRAM/DDR1/DDR2 controller is the only bus slave on the
Rbus. It includes an Advanced Memory Scheduler to arbitrate the requests from bus masters, enhancing the
performance of memory access intensive tasks.
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Table of Contents
1. MIPS 24K PROCESSOR 11
1.1FEATURES11
1.2BLOCK DIAGRAM12
1.3MEMORY MAP SUMMARY13
1.4CLOCK PLAN14
1.5CPUCLOCK MUX15
2. REGISTERS 16
2.1NOMENCLATURE16
2.2SYSTEM CONTROL17
2.2.1FEATURES17
2.2.2BLOCK DIAGRAM17
2.2.3LIST OF REGISTERS18
2.2.4REGISTER DESCRIPTIONS (BASE:0X1000_0000) 19
2.3TIMER46
2.3.1FEATURES46
2.3.2BLOCK DIAGRAM47
2.3.3LIST OF REGISTERS48
2.3.4REGISTER DESCRIPTIONS (BASE:0X1000_0100) 49
2.4INTERRUPT CONTROLLER53
2.4.1FEATURES53
2.4.2BLOCK DIAGRAM53
2.4.3LIST OF REGISTERS54
2.4.4REGISTER DESCRIPTIONS (BASE:0X1000_0200) 55
2.5SYSTEM TICK COUNTER60
2.5.1LIST OF REGISTERS60
2.5.2REGISTER DESCRIPTIONS (BASE:0X1000_0D00) 61
2.6UART 62
2.6.1FEATURES62
2.6.2BLOCK DIAGRAM62
2.6.3LIST OF REGISTERS63
2.6.4REGISTER DESCRIPTIONS (BASE:0X1000_0500) 64
2.7UARTLITE72
2.7.1FEATURES72
2.7.2BLOCK DIAGRAM72
2.7.3LIST OF REGISTERS73
2.7.4REGISTER DESCRIPTIONS (BASE:0X1000_0C00) 74
2.8PROGRAMMABLE I/O 81
2.8.1FEATURES81
2.8.2BLOCK DIAGRAM81
2.8.3LIST OF REGISTERS82
2.8.4REGISTER DESCRIPTIONS (BASE:0X1000_0600) 84
2.9I2CCONTROLLER97
2.9.1FEATURES97
2.9.2BLOCK DIAGRAM97
2.9.3LIST OF REGISTERS98
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FIGURE 4-1TXD AND TX FRAME INFORMATION ............................................................................................................ 481
FIGURE 4-6RXWIFRAME FORMAT ............................................................................................................................ 492
TABLE 2-4RATE CONTROL ........................................................................................................................................ 249
TABLE 2-5RULE CONTROL ........................................................................................................................................ 249
MIPS32 Enhanced Architecture (Release 2) Features
Vectored interrupts and support for an external interrupt controller
Programmable exception vector base
Atomic interrupt enable/disable
GPR shadow registers (one, three or seven additional shadows can be optionally added to minimize
latency for interrupt handlers)
Bit field manipulation instructions
MIPS32 Privileged Resource Architecture
MIPS DSP ASE
Fractional data types (Q15, Q31)
Saturating arithmetic
SIMD instructions operate on 2x16 b or 4x8 b simultaneously
3 additional pairs of accumulator registers
16-bit encodings of 32-bit instructions to improve code density
Special PC-relative instructions for efficient loading of addresses and constants
SAVE & RESTORE macro instructions for setting up and tearing down stack frames within subroutines
Improved support for handling 8 and 16-bit datatypes
Integrated 802.11n MAC/BBP and 2.4 GHz RF/FEM Router-on-a-Chip
2. Registers
2.1 Nomenclature
The following nomenclature is used for register types:
RO Read Only
WO Write Only
RW Read or Write
RC Read Clear
W1C Write One Clear
- Reserved bit
X Undefined binary value
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System Control
Registers
PalmBus Interface
System Control Block
CPU Rbus Wrapper
Pin Muxing Block
Platform Blocks
PCIe, PCM, ...
Boot Strapping Signals
Cache Hit/Miss Strobes
To/From MIPS
Memory Remapping
GPIO Pin Muxing Scheme
Per Block S/W Reset
Miscellaneous Registers
2.2 System Control
2.2.1 Features
Provides read-only chip revision registers
Provides a window to access boot-strapping signals
Supports memory remapping configurations
Supports software reset to each platform building block
Provides registers to determine GPIO and other peripheral pin muxing schemes
Provides some power-on-reset only test registers for software programmers
Combines miscellaneous registers (such as clock skew control, status register, memo registers, etc)
2.2.2 Block Diagram
Figure 2-1 System Control Block Diagram
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No.
Offset
Register Name
Description
Page
1
0x0000
CHIPID0_3
Chip ID ASCII Character 0-3
19 2 0x0004
CHIPID4_7
Chip ID ASCII Character 4-7
19 3 0x000C
REVID
Chip Revision Identification
19 4 0x0010
SYSCFG0
System Configuration Register 0
19 5 0x0014
SYSCFG1
System Configuration Register 1
20 6 0x0018
TESTSTAT
Firmware Test Status Register
22 7 0x001C
TESTSTAT2
Firmware Test Status Register 2
22
8
0x0020
Reserved
-
22
9
0x0024
Reserved
-
23
10
0x0028
Reserved
-
23
11
0x002C
CLKCFG0
Clock Configuration Register 0
23
12
0x0030
CLKCFG1
Clock Configuration Register 1
24
13
0x0034
RSTCTRL
Reset Control
25
14
0x0038
RSTSTAT
Reset Status
26
15
0x003C
CPU_SYS_CLKCFG
CPU and SYS Clock Control
27
16
0x0040
CLK_LUT_CFG
Clock Look Up Table Configuration
29
17
0x0044
CUR_CLK_STS
Current clock status
30
18
0x0048
BPLL_CFG0
BB PLL Configuration 0
31
19
0x004C
BPLL_CFG1
BB PLL Configuration 1
31
20
0x0054
CPLL_CFG0
CPU PLL Configuration 0
33
21
0x0058
CPLL_CFG1
CPU PLL Configuration 1
36
22
0x005C
USB_PHY_CFG
USB PHY control
36
23
0x0060
GPIOMODE
GPIO Purpose Select
36
24
0x0064
PCIPDMA_STAT
Control and Status of PDMA in PCIe Device
39
25
0x0088
PMU0_CFG
Power Management Unit 0 Configuration
39
26
0x008C
PMU1_CFG
Power Management Unit 1 Configuration
40
27
0x0098
PPLL_CFG0
PCIe PLL Configuration 0
41
28
0x009C
PPLL_CFG1
PCIe PLL Configuration 1
43
29
0x00A0
PPLL_DRV
PCIe Driver Configuration
44
2.2.3 List of Registers
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Bits
Type
Name
Description
Initial Value
31:24
RO
CHIP_ID3
ASCII CHIP Name Identification Character 3
0x36
23:16
RO
CHIP_ID2
ASCII CHIP Name Identification Character 2
0x37
15:8
RO
CHIP_ID1
ASCII CHIP Name Identification Character 1
0x54
7:0
RO
CHIP_ID0
ASCII CHIP Name Identification Character 0
0x4D
Bits
Type
Name
Description
Initial Value
31:24
RO
CHIP_ID7
ASCII CHIP Name Identification Character 7
0x20
23:16
RO
CHIP_ID6
ASCII CHIP Name Identification Character 6
0x20
15:8
RO
CHIP_ID5
ASCII CHIP Name Identification Character 5
0x30
7:0
RO
CHIP_ID4
ASCII CHIP Name Identification Character 4
0x32
Bits
Type
Name
Description
Initial Value
31:17
- - Reserved
0x0
16
RO
PKG_ID
Package ID
0: DRQFN-148 pin
1: TFBGA-269 ball
NOTE: This value is determined by the package
used.
-
15:12
- - Reserved
0x0
11:8
RO
VER_ID
Chip Version Number
0x2
7:4 - -
Reserved
0x0
3:0
RO
ECO_ID
Chip ECO Number
0x1
Bits
Type
Name
Description
Initial Value
31:24
RW
TEST_CODE
Test Code
Default value is from bootstrap and can be
modified by software.
0x0
23 - -
Reserved
0x0
22:12
RO
BS_SHADOW
BS shadow register for last boot-up value
Displays a backup copy of the last bootup value.
BS
11:9
- - Reserved
0x0
2.2.4 Register Descriptions (base: 0x1000_0000)
1. CHIPID0_3: Chip ID ASCII Character 0-3 (offset: 0x0000)
2. CHIPID4_7: Chip Name ASCII Character 4-7 (offset: 0x0004)
4. SYSCFG0: System Configuration Register 0 (offset: 0x0010)
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Bits
Type
Name
Description
Initial Value
8
RO
DRAM_FROM_EE
DRAM Configuration from EEPROM
0: DRAM/PLL configuration from EEPROM.
1: DRAM configuration from Auto Detect.
For more information see the Bootstrapping
Pins Description in the datasheet for this chip.
Chip Mode
A vector to set chip function/test/debug modes
in non-test/debug operation.
For more information see the Bootstrapping
Pins Description in the datasheet for this chip.
BS
Bits
Type
Name
Description
Initial Value
31:30
- - Reserved
-
29:28
RW
DDR_DPIN_RXPWD
SDRAM Data Pin Receiver Circuit Power Down
Control*
(DQ/DQS)
0: Disable (SDR/DDR1/DDR2 default)
1: Enable
2: Enable while data pin is output mode.
3: Enable while data pin is input mode.
BS
27:26
RW
DDR_DPIN_ODT
SDRAM Data Pin On Die Termination Setting*
(DQ/DQS)
[27:26]
SDR
(3.3 V)
SDR
(2.5 V/
1.8 V)
DDR1
DDR2
0
(Disable)
(Disable)
(Disable)
(Disable)
1
75 Ω
75 Ω
75 Ω
75 Ω
2
150 Ω
150 Ω
150 Ω
150 Ω
3
N/A
N/A
N/A
N/A
BS
5. SYSCFG1: System Configuration Register 0 (offset: 0x0014)
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Bits
Type
Name
Description
Initial Value
25:24
RW
DDR_DPIN_DRV
SDRAM Data Pin Driving Setting*
(DQ/DQS/DQM)
[25:24]
SDR
(3.3 V)
SDR
(2.5 V/
1.8 V)
DDR1
DDR2
0
N/A
10 mA
Class II
Full 1 N/A
8 mA
N/A
N/A 2 16 mA
4 mA
(Class I)
(Half)
3
(8 mA)
(2 mA)
N/A
N/A
BS
23 - -
Reserved
-
22
RW
DDR_CPIN_RXPWD
SDRAM Command Pin Receiver Circuit Power
Down Control*
(MA/MBA/MCS_N/MWE_N/MRAS_N/
MCAS_N/ MCKE)
0: Disable power down
1: Enable power down (SDR/DDR1/DDR2
default)
Oscillator 1 μs Divider
Sets the maximum for the reference clock
counter for either a 20 MHz or 40 MHz external
XTAL input. The count increments each 1 μsec
(indicating 1 MHz), up to the maximum, before
resetting to zero. This counts the frequency of
an external XTAL. This count is used to output a
32 KHz frequency to the REFCLK0 pin.
6’b0: Automatically generates a 1 μs system tick
regardless of whether XTAL frequency is 20
MHz or 40 MHz.
6’d39: Default value for an external 40 MHz
XTAL.
6’d19: Default value for an external 20 MHz
XTAL.
Others: Manual mode for tick generation.
0x0
23
-
-
Reserved
0x0
22:18
RW
INT_CLK_FDIV
Internal Clock Frequency Divider
The frequency divider used to generate the
Fraction-N clock frequency.
Valid values range from 1 to 31.
Fraction-N clock frequency =
(INT_CLK_FFRAC/INT_CLK_FDIV)*PLL_FREQ
Integrated 802.11n MAC/BBP and 2.4 GHz RF/FEM Router-on-a-Chip
Bits
Type
Name
Description
Initial Value
16:12
RW
INT_CLK_FFRAC
Internal Clock Fraction-N Frequency
A parameter used in conjunction with
INT_CLK_FDIV to generate the Fraction-N clock
frequency.
Valid values range from 0 to 31.
Fraction-N clock Frequency =
(INT_CLK_FFRAC/INT_CLK_FDIV)*PLL_FREQ
Peripheral Clock Source Select
Sets the peripheral clock to use the 20/40 MHz
frequency input from XTAL.
0: 40 MHz from 480 MHz divided by 12.
1: 20 MHz/40M Hz from XTAL input
0x0
3
RW
EPHY_USE_25M
EPHY Clock Source Select
Set the EPHY clock to use the 25 MHz frequency
input from the PPLL.
0: EPHY use 20/40 MHz from XTAL
1: EPHY use 25 MHz from PPLL
Integrated 802.11n MAC/BBP and 2.4 GHz RF/FEM Router-on-a-Chip
Bits
Type
Name
Description
Initial Value
22 - -
Reserved
0x1
21
RW
FE_ CLK_EN
FE clock enable
0x1
20 - -
Reserved
0x0
19
RW
UARTL_ CLK_EN
UART Lite clock enable
0x1
18
RW
SPI CLK_EN
SPI clock enable
0x1
17
RW
I2S CLK_EN
I2S clock enable
0x1
16
RW
I2C CLK_EN
I2C clock enable
0x1
15
RW
NAND_CLK_EN
Nand flash control clock enable
0x1
14
RW
GDMA CLK_EN
GDMA clock enable
0x1
13
RW
PIO CLK_EN
GPIO controller clock enable
0x1
12
RW
UART_ CLK_EN
UART clock enable
0x1
11
RW
PCM_ CLK_EN
PCM clock enable
0x1
10
RW
MC_ CLK_EN
Memory controller clock enable
0x1
9
RW
INTC_ CLK_EN
Interrupt controller clock enable
0x1
8
RW
TIMER_CLK_EN
Timer clock enable
0x1
7
RW
GE2_CLK_EN
GE2 controller clock enable.
0x1
6
RW
GE1_CLK_EN
GE1 controller clock enable.
0x1
5:0 - -
Reserved
0x0
Bits
Type
Name
Description
Initial Value
31
RW
PPE_RST
Resets PPE
0x0
30
RW
SDHC_RST
Resets SD Controller.
0x0
29 - -
Reserved
0x0
28
RW
MIPS_CNT_RST
Resets MIPS counter block.
0x0
27 - -
Reserved
0x0
26
RW
PCIE0_RST
Resets PCIE Host Bridge, PCIE0 Controller and
PHY.
0x0
25
RW
UHST0_RST
Resets USB PHY0.
NOTE: USB Host controller will be reset when
both UHST0_RST and UHST1_RST are set.
0x0
24
RW
EPHY_RST
Resets the Ethernet PHY block.
0x0
23
RW
ESW_RST
Resets the Ethernet switch block.
0x0
22 - -
Reserved
0x0
21
RW
FE_RST
Resets the Frame Engine block.
0x0
20
RW
WLAN_RST-
Resets the WLAN block.
0x0
19
RW
UARTL_RST
Resets the UART Lite block.
0x0
NOTE:
0: Clock is gated.
1: Clock is enabled.
13. RSTCTRL: Reset Control Register (offset: 0x0034)
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Bits
Type
Name
Description
Initial Value
18
RW
SPI
Resets the SPI block.
0x0
17
RW
I2S
Resets the I2S block.
0x0
16
RW
I2C
Resets the I2C block.
0x0
15
RW
NAND
Resets the NAND block.
0x0
14
RW
DMA
Resets the DMA block.
0x0
13
RW
PIO
Resets the PIO block.
0x0
12
RW
UART_RST
Resets the UART block.
0x0
11
RW
PCM_RST
Resets the PCM block.
0x0
10
RW
MC_RST
Resets the Memory Controller block.
0x1
9
RW
INTC_RST
Resets the Interrupt Controller block.
0x0
8
RW
TIMER_RST
Resets the Timer block.
0x0
7:1 - -
Reserved
0x0
0
W1C
SYS_RST
Resets the whole SoC.
0x0
Bits
Type
Name
Description
Initial Value
31
RW
WDT2SYSRST_EN
Watchdog Timeout To System Reset Enable
Enables watchdog timeout to trigger a system
reset.
0: Disable
1: Enable
0x1
30
RW
WDT2RSTO_EN
Watchdog Timeout to Reset Output Enable
Enables watchdog timeout to trigger the reset
output pin.
0: Disable
1: Enable
0x1
29:16
RW
WDTRSTPD
Watchdog Reset Output Low Period
Controls the WDT reset output low period. For
example:
If the pin share mode was set correctly and
WDT2RSTO_EN=1,
When WDTRSTPD= 0, you can see duration
of 1 μs low on the WDT reset output pin.
When WDTRSTPD= 3, you can see duration
of 4 μs low on the WDT reset output pin.
(unit: 1 μs)
0x3
15:4
- - Reserved
0x0
NOTE:
0: Deassert reset
1: Reset
14. RSTSTAT: Reset Status Register (offset: 0x0038)
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Bits
Type
Name
Description
Initial Value
3
R/W1C
SWCPURST
Software CPU Reset
Indicates when software has reset the CPU by
writing to the RSTCPU bit in RSTCTL.
0: Has no effect.
1: Clears this bit.
NOTE: This register is reset only by a power-on
reset.
0x0
2
R/W1C
SWSYSRST
Software System Reset
Indicates when software has reset the chip by
writing to the RSTSYS bit in RSTCTL.
0: Has no effect.
1: Clears this bit.
NOTE: This register is reset only by a power on
reset.
0x0
1
R/W1C
WDRST
Watchdog Reset
Indicates when the watchdog timer has reset
the chip.
0: Has no effect.
1: Clears this bit.
NOTE: This register is reset only by power-on
reset.
0x0
0 - -
Reserved
0x0
Bits
Type
Name
Description
Initial Value
31:20
- - Reserved
0x0
19:16
RW
CPU_OCP_RATIO
CPU OCP Ratio
The ratio between the system bus frequency
and the CPU frequency.
Value
Ratio (SYS : CPU )
4’d0
1 : 1 (Reserved)
4’d1
1 : 1.5 (Reserved)
4’d2
1 : 2
4’d3
1 : 2.5 (Reserved)
4’d4
1 : 3
4’d5
1 : 3.5 (Reserved)
4’d6
1 : 4
4’d7
1 : 5
4’d8
1 : 10
Others
Reserved
NOTE: If the chip runs in USB OHCI mode, the
OCP frequency cannot be lower than 30 MHz. It
means that
PLL_FREQ*(CPU_FFRAC/CPU_FDIV)/(CPU_OCP_
RATIO+1) >= 30 MHz.
0x4
15:13
- - Reserved
0x0
15. CPU_SYS_CLKCFG: CPU and SYS Clock Control (offset: 0x003C)
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Bits
Type
Name
Description
Initial Value
12:8
RW
CPU_FDIV
CPU Frequency Divider
The frequency divider is used to generate the
CPU frequency. The value must be larger than
or equal to CPU_FFRAC. Valid values range from
1 to 31.
0xA
7:5 - -
Reserved
0x0
4:0
RW
CPU_FFRAC
CPU Frequency Fractional
A parameter used in conjunction with the CPU
frequency divider to determine the CPU
frequency. Input a value in the following
equation to determine the CPU frequency.
Valid values range from 0 to 31.
CPU frequency =
(CPU_FFRAC/CPU_FDIV)*PLL_FREQ
NOTE: If the chip runs in USB OHCI mode, the
OCP frequency cannot be lower than 30 MHz. It
means that
PLL_FREQ*(CPU_FFRAC/CPU_FDIV)/(CPU_OCP_
RATIO+1) >= 30 MHz.
0x1
NOTE:
1. Equation used to derive system frequency after chip boot up:
Integrated 802.11n MAC/BBP and 2.4 GHz RF/FEM Router-on-a-Chip
Bits
Type
Name
Description
Initial Value
31
RW
SLP_EN
Sleep Mode Enable
Enables sleep mode when MIPS SI_Sleep is
asserted.
0: Disable
1: Enable
Sleep Mode CPU Frequency =
(1/CPU_FDIV)*PLL_FREQ
0x0
30
RW
STEP_EN
Step Jump Enable
Enables step jump after MIPS exits sleep mode.
The CPU will jump to the normal frequency in
increments defined by STEP_FFRAC.bit[4:0] of
this register.
0: Disable
1: Enable
0x0
29:28
- - Reserved
0x0
27:20
RW
STEP_CNT
Step Counter
Sets the period of each step jump. When the
counter counts down to zero, the CPU clock
automatically changes to the next step
frequency.
The count period unit is 1 μs.
0x2
19:16
RW
SLP_OCP_RATIO
Sleep Mode CPU and System Bus Frequency
Ratio
Sets the ratio between the system bus frequency
and the CPU frequency when entering sleep
mode. (SYS:CPU)
Value
Ratio (SYS : CPU )
4’d0
1 : 1
4’d1
1 : 1.5 (Reserved)
4’d2
1 : 2
4’d3
1 : 2.5 (Reserved)
4’d4
1 : 3
4’d5
1 : 3.5 (Reserved)
4’d6
1 : 4
4’d7
1 : 5
4’d8
1 : 10
Others
Reserved
0x4
15:5
- - Reserved
0x0
16. CLK_LUT_CFG: CPU and SYS Clock Auto Control (offset: 0x0040)
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Bits
Type
Name
Description
Initial Value
4:0
RW
STEP_FFRAC
Step Frequency Fraction
Sets the fractional size of the increment in CPU
frequency after the CPU exits from sleep mode
and returns to normal operation. This step is
only valid when SLP_STEP_EN is enabled.
FRAC_VALUE =
PREVIOUS_FRAC_VALUE + STEP_FFRAC
CPU Frequency =
(FRAC_VALUE/CPU_FDIV)*PLL_FREQ
0x6
Bits
Type
Name
Description
Initial Value
31:21
- - Reserved
0x0
20
RO
SAME_FREQ
Indicates that the SYS and DRAM clocks are on
the same frequency.
0: False
1: True
-
19:16
RO
CUR_OCP_RATIO
Current CPU_OCP_Ratio (SYS : CPU)
Shows the current ratio between the system bus
and CPU frequencies.
Value
Ratio (SYS : CPU )
4’d0
1 : 1
4’d1
1 : 1.5 (Reserved)
4’d2
1 : 2
4’d3
1 : 2.5 (Reserved)
4’d4
1 : 3
4’d5
1 : 3.5 (Reserved)
4’d6
1 : 4
4’d7
1 : 5
4’d8
1 : 10
Others
Reserved
-
15:13
- - Reserved
0x0
12:8
RO
CUR_CPU_FDIV
Current CPU Frequency Divider
The frequency divider is used to generate the
CPU frequency.
For more information, see CPU_SYS_CLKCFG,
offset 0x003C, bit[12:8].
0xA
7:5 - -
Reserved
0x0
4:0
RO
CUR_CPU_FFRAC
Current CPU Frequency Fraction
A parameter used in conjunction with the CPU
frequency divider to determine the CPU
frequency.
For more information, see CPU_SYS_CLKCFG,
offset 0x003C, bit[4:0].
0x1
17. CUR_CLK_STS: Current Clock Status (offset: 0x0044)
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