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Diffstat (limited to 'doc/README.socfpga')
| -rw-r--r-- | doc/README.socfpga | 32 |
1 files changed, 0 insertions, 32 deletions
diff --git a/doc/README.socfpga b/doc/README.socfpga index cfcbbfe..e717637 100644 --- a/doc/README.socfpga +++ b/doc/README.socfpga @@ -14,40 +14,8 @@ socfpga_dw_mmc Here are macro and detailed configuration required to enable DesignWare SDMMC controller support within SOCFPGA -#define CONFIG_MMC --> To enable the SD MMC framework support - -#define CONFIG_SDMMC_BASE (SOCFPGA_SDMMC_ADDRESS) --> The base address of CSR register for DesignWare SDMMC controller - #define CONFIG_GENERIC_MMC -> Enable the generic MMC driver #define CONFIG_SYS_MMC_MAX_BLK_COUNT 256 -> Using smaller max blk cnt to avoid flooding the limited stack in OCRAM - -#define CONFIG_DWMMC --> Enable the common DesignWare SDMMC controller framework - -#define CONFIG_SOCFPGA_DWMMC --> Enable the SOCFPGA specific driver for DesignWare SDMMC controller - -#define CONFIG_SOCFPGA_DWMMC_FIFO_DEPTH 1024 --> The FIFO depth for SOCFPGA DesignWare SDMMC controller - -#define CONFIG_SOCFPGA_DWMMC_DRVSEL 3 --> Phase-shifted clock of sdmmc_clk for controller to drive command and data to -the card to meet hold time requirements. SD clock is running at 50MHz and -drvsel is set to shift 135 degrees (3 * 45 degrees). With that, the hold time -is 135 / 360 * 20ns = 7.5ns. - -#define CONFIG_SOCFPGA_DWMMC_SMPSEL 0 --> Phase-shifted clock of sdmmc_clk used to sample the command and data from -the card - -#define CONFIG_SOCFPGA_DWMMC_BUS_WIDTH 4 --> Bus width of data line which either 1, 4 or 8 and based on board routing. - -#define CONFIG_SOCFPGA_DWMMC_BUS_HZ 50000000 --> The clock rate to controller. Do note the controller have a wrapper which -divide the clock from PLL by 4. |