Hi @mjbcswitzerland
Just a short summary, to explain where we are in our journey of getting our second flash working:
- we have a custom board (with an IMX RT 1024), where secondary flash module is connected to FlexSPI port B
- the pin normally used for DQS for FlexSPI A1 (SD_B1_05) is used for SS0 on flash B in our schema
- so we have no other option to mux SD_B1_05 for FlexSPI B SS0, and thus accept the clock frequency of 60 MHz for both flashes
We are attempting to get a proof of life in the nor transfer polling example. Our current set of changes in this SDK example are:
1. disable FlexSPI A DQS muxing
The IMX RT 1024 has a weird difference compared to any other CPU in the IMX RT family as for as I know; something funky with ROM code not supporting DQS natively. Why, I don't know, but to compensate for this, the SDK examples mux DQS in the startup code. Since we need SD_B1_05 for second flash (B1), I commented out this line in the Startup/SystemInit.
/* Configure FLEXSPI_A_DQS */
// Commented out, we need SD_B1_05 for FlexSPI B SS0 function
// IOMUXC -> SW_MUX_CTL_PAD[86] = IOMUXC_SW_MUX_CTL_PAD_MUX_MODE(1) | IOMUXC_SW_MUX_CTL_PAD_SION(1);
2. Set flex spi clock to 60 MHz
Since we can't use DQS for Flash A, we must ensure that flex spi clock runs at 60 MHz). For this, we need to that the sample clock source is set to loopback internally (instead of LoopbackFromDqsPad), and set the clock to 60 MHz. For the 1024, this is also "overriden" in startup code in the SystemInit function. So same file, another small change:
/* Re-Configure FLEXSPI NOR via ROM API, for details please refer to the init function of ROM FLEXSPI NOR flash
driver which is in fsl_romapi.h and fsl_romapi.c in the devices\${soc}\drivers directory of SDK package */
uint8_t flexspi_nor_config[512];
memcpy((void *)flexspi_nor_config, (void *)FLASH_CONFIG_ADDRESS, sizeof(flexspi_nor_config));
// Original values in SDK example
// flexspi_nor_config[12] = 1U; /* kFLEXSPIReadSampleClk_LoopbackFromDqsPad */
// flexspi_nor_config[70] = 7U; /* kFLEXSPISerialClk_133MHz */
flexspi_nor_config[12] = 0U; /* kFLEXSPIReadSampleClk_LoopbackInternally */
flexspi_nor_config[70] = 1U; /* kFLEXSPISerialClk_69MHz */
flexspi_nor_init_t flash_init = (flexspi_nor_init_t)ROM_FLASH_INIT_ADDRESS;
flash_init(0U, flexspi_nor_config);
#endif /* #if defined(XIP_BOOT_HEADER_ENABLE) && (XIP_BOOT_HEADER_ENABLE == 1) */
Next to that, I configured the pins for flexspi B in the pin tool, and had it generate the muxing in pinmux.c
IOMUXC_SetPinMux(
IOMUXC_GPIO_SD_B1_00_FLEXSPI_B_DATA03, /* GPIO_SD_B1_00 is configured as FLEXSPI_B_DATA03 */
0U); /* Software Input On Field: Input Path is determined by functionality */
IOMUXC_SetPinMux(
IOMUXC_GPIO_SD_B1_01_FLEXSPI_B_SCLK, /* GPIO_SD_B1_01 is configured as FLEXSPI_B_SCLK */
0U); /* Software Input On Field: Input Path is determined by functionality */
IOMUXC_SetPinMux(
IOMUXC_GPIO_SD_B1_02_FLEXSPI_B_DATA00, /* GPIO_SD_B1_02 is configured as FLEXSPI_B_DATA00 */
0U); /* Software Input On Field: Input Path is determined by functionality */
IOMUXC_SetPinMux(
IOMUXC_GPIO_SD_B1_03_FLEXSPI_B_DATA02, /* GPIO_SD_B1_03 is configured as FLEXSPI_B_DATA02 */
0U); /* Software Input On Field: Input Path is determined by functionality */
IOMUXC_SetPinMux(
IOMUXC_GPIO_SD_B1_04_FLEXSPI_B_DATA01, /* GPIO_SD_B1_04 is configured as FLEXSPI_B_DATA01 */
0U); /* Software Input On Field: Input Path is determined by functionality */
IOMUXC_SetPinMux(
IOMUXC_GPIO_SD_B1_05_FLEXSPI_B_SS0_B, /* GPIO_SD_B1_05 is configured as FLEXSPI_B_SS0_B */
0U); /* Software Input On Field: Input Path is determined by functionality */
And finally, I adapted the more obvious required changes in the SDK example "user code".
- In app.h I selected FlexSPI port B1, and loopback internally.
#define EXAMPLE_FLEXSPI FLEXSPI
#define FLASH_SIZE 0x1000 /* 32Mb/KByte */
#define EXAMPLE_FLEXSPI_AMBA_BASE FlexSPI_AMBA_BASE
#define FLASH_PAGE_SIZE 256
#define EXAMPLE_SECTOR 6
#define SECTOR_SIZE 0x1000 /* 4K */
#define EXAMPLE_FLEXSPI_CLOCK kCLOCK_FlexSpi
#define FLASH_PORT kFLEXSPI_PortB1 /* was kFLEXSPI_PortA1 */
#define EXAMPLE_FLEXSPI_RX_SAMPLE_CLOCK kFLEXSPI_ReadSampleClkLoopbackInternally /* was kFLEXSPI_ReadSampleClkLoopbackFromDqsPad */
- In the flexspi_nor_polling_transfer.c (the "main" of the SDK example) I specified the clock speed of 60MHz
flexspi_device_config_t deviceconfig = {
.flexspiRootClk = 60000000, // was 133000000
.flashSize = FLASH_SIZE,
.CSIntervalUnit = kFLEXSPI_CsIntervalUnit1SckCycle,
.CSInterval = 2,
.CSHoldTime = 3,
.CSSetupTime = 3,
.dataValidTime = 0,
.columnspace = 0,
.enableWordAddress = 0,
.AWRSeqIndex = 0,
.AWRSeqNumber = 0,
.ARDSeqIndex = NOR_CMD_LUT_SEQ_IDX_READ_FAST_QUAD,
.ARDSeqNumber = 1,
.AHBWriteWaitUnit = kFLEXSPI_AhbWriteWaitUnit2AhbCycle,
.AHBWriteWaitInterval = 0,
};
You wrote:
"When FlexSPI B is used the application needs to configure everything (The pins, FlexSPI registers, LUT, etc.) and so the SDK references are sited as reference to how to do it."
So far I think I have all bases covered. The pins for FlexSPI B are muxed, the LUT is provided by the SDK example. They are the same for our flash (we used the flash module shipped with the 1021 EVK as secondary flash).
Except, I still don't know how to tell FlexSPI that I have a second flash module, and that this module is 8MB large. So I thought the only option was to configure this in the XIP bytes, which also specifies the size of flash A, since that struct allows me to also specify the size for flash B1.
const flexspi_nor_config_t qspiflash_config = {
.memConfig =
{
.tag = FLEXSPI_CFG_BLK_TAG,
.version = FLEXSPI_CFG_BLK_VERSION,
.readSampleClksrc=kFlexSPIReadSampleClk_LoopbackInternally,
.csHoldTime = 3u,
.csSetupTime = 3u,
.controllerMiscOption = (1u << kFlexSpiMiscOffset_SafeConfigFreqEnable),
.deviceType = kFlexSpiDeviceType_SerialNOR,
.sflashPadType = kSerialFlash_4Pads,
.serialClkFreq = kFlexSpiSerialClk_60MHz,
.sflashA1Size = 4u * 1024u * 1024u,
.sflashB1Size = 8u * 1024u * 1024u, // I understand now that this is wrong!
.lookupTable =
I now understand this is incorrect. But I still don't know where I should specify it.
What am I still missing?
