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stm32/sdram: Make SDRAM refresh count configurable by a board.

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Refresh count calculations were using a hard-coded SDRAM frequency and
refresh cycles, so change them to values that can be set by a board.

And set these options to their existing values on STM32F769DISC and
STM32F7DISC boards.

Signed-off-by: iabdalkader <i.abdalkader@gmail.com>
This commit is contained in:
iabdalkader 2024-11-30 09:56:23 +01:00 committed by Damien George
parent 47d9988df2
commit 17808e7b74
3 changed files with 7 additions and 3 deletions
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2
ports/stm32/boards/STM32F769DISC/mpconfigboard.h
View file

@ -141,6 +141,7 @@ extern struct _spi_bdev_t spi_bdev;
#define MICROPY_HW_SDRAM_BURST_LENGTH 1 #define MICROPY_HW_SDRAM_BURST_LENGTH 1
#define MICROPY_HW_SDRAM_CAS_LATENCY 2 #define MICROPY_HW_SDRAM_CAS_LATENCY 2
#define MICROPY_HW_SDRAM_FREQUENCY_KHZ (90000) // 90 MHz
#define MICROPY_HW_SDRAM_COLUMN_BITS_NUM 8 #define MICROPY_HW_SDRAM_COLUMN_BITS_NUM 8
#define MICROPY_HW_SDRAM_ROW_BITS_NUM 12 #define MICROPY_HW_SDRAM_ROW_BITS_NUM 12
#define MICROPY_HW_SDRAM_MEM_BUS_WIDTH 32 #define MICROPY_HW_SDRAM_MEM_BUS_WIDTH 32
@ -150,6 +151,7 @@ extern struct _spi_bdev_t spi_bdev;
#define MICROPY_HW_SDRAM_RBURST (1) #define MICROPY_HW_SDRAM_RBURST (1)
#define MICROPY_HW_SDRAM_WRITE_PROTECTION (0) #define MICROPY_HW_SDRAM_WRITE_PROTECTION (0)
#define MICROPY_HW_SDRAM_AUTOREFRESH_NUM (8) #define MICROPY_HW_SDRAM_AUTOREFRESH_NUM (8)
#define MICROPY_HW_SDRAM_REFRESH_CYCLES 8192
// See pins.csv for CPU pin mapping // See pins.csv for CPU pin mapping
#define MICROPY_HW_FMC_SDCKE0 (pyb_pin_FMC_SDCKE0) #define MICROPY_HW_FMC_SDCKE0 (pyb_pin_FMC_SDCKE0)

2
ports/stm32/boards/STM32F7DISC/mpconfigboard.h
View file

@ -111,6 +111,7 @@ void STM32F7DISC_board_early_init(void);
#define MICROPY_HW_SDRAM_BURST_LENGTH 1 #define MICROPY_HW_SDRAM_BURST_LENGTH 1
#define MICROPY_HW_SDRAM_CAS_LATENCY 2 #define MICROPY_HW_SDRAM_CAS_LATENCY 2
#define MICROPY_HW_SDRAM_FREQUENCY_KHZ (90000) // 90 MHz
#define MICROPY_HW_SDRAM_COLUMN_BITS_NUM 8 #define MICROPY_HW_SDRAM_COLUMN_BITS_NUM 8
#define MICROPY_HW_SDRAM_ROW_BITS_NUM 12 #define MICROPY_HW_SDRAM_ROW_BITS_NUM 12
#define MICROPY_HW_SDRAM_MEM_BUS_WIDTH 16 #define MICROPY_HW_SDRAM_MEM_BUS_WIDTH 16
@ -120,6 +121,7 @@ void STM32F7DISC_board_early_init(void);
#define MICROPY_HW_SDRAM_RBURST (1) #define MICROPY_HW_SDRAM_RBURST (1)
#define MICROPY_HW_SDRAM_WRITE_PROTECTION (0) #define MICROPY_HW_SDRAM_WRITE_PROTECTION (0)
#define MICROPY_HW_SDRAM_AUTOREFRESH_NUM (8) #define MICROPY_HW_SDRAM_AUTOREFRESH_NUM (8)
#define MICROPY_HW_SDRAM_REFRESH_CYCLES 8192
#define MICROPY_HW_FMC_SDCKE0 (pin_C3) #define MICROPY_HW_FMC_SDCKE0 (pin_C3)
#define MICROPY_HW_FMC_SDNE0 (pin_H3) #define MICROPY_HW_FMC_SDNE0 (pin_H3)

6
ports/stm32/sdram.c
View file

@ -245,15 +245,15 @@ static void sdram_init_seq(SDRAM_HandleTypeDef
/* Send the command */ /* Send the command */
HAL_SDRAM_SendCommand(hsdram, command, 0x1000); HAL_SDRAM_SendCommand(hsdram, command, 0x1000);
/* Step 8: Set the refresh rate counter /* Step 8: Set the refresh rate counter.
Assuming 90MHz frequency, 8192 refresh cycles and 64ms refresh rate:
RefreshRate = 64 ms / 8192 cyc = 7.8125 us/cyc RefreshRate = 64 ms / 8192 cyc = 7.8125 us/cyc
RefreshCycles = 7.8125 us * 90 MHz = 703 RefreshCycles = 7.8125 us * 90 MHz = 703
According to the formula on p.1665 of the reference manual, According to the formula on p.1665 of the reference manual,
we also need to subtract 20 from the value, so the target we also need to subtract 20 from the value, so the target
refresh rate is 703 - 20 = 683. refresh rate is 703 - 20 = 683.
*/ */
#define REFRESH_COUNT (MICROPY_HW_SDRAM_REFRESH_RATE * 90000 / 8192 - 20) #define REFRESH_COUNT (MICROPY_HW_SDRAM_REFRESH_RATE * MICROPY_HW_SDRAM_FREQUENCY_KHZ / MICROPY_HW_SDRAM_REFRESH_CYCLES - 20)
HAL_SDRAM_ProgramRefreshRate(hsdram, REFRESH_COUNT); HAL_SDRAM_ProgramRefreshRate(hsdram, REFRESH_COUNT);
#if defined(STM32F7) || defined(STM32H7) #if defined(STM32F7) || defined(STM32H7)