From: Gabriel Somlo Date: Mon, 3 Aug 2020 16:03:39 +0000 (-0400) Subject: liblitesdcard/sdcard: (temporarily) slow down SDCARD_CLK_FREQ to 25MHz X-Git-Tag: 24jan2021_ls180~36^2~1 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=df3428be07ff82aceac67297e38793e56641f206;p=litex.git liblitesdcard/sdcard: (temporarily) slow down SDCARD_CLK_FREQ to 25MHz Rocket's DMA slave interface (and/or internal routing) currently appears unable to route DMA writes from LiteSDCard at frequencies above 25MHz (as tested on nexys4ddr, with Rocket, at 75MHz main system clock frequency). Signed-off-by: Gabriel Somlo --- diff --git a/litex/soc/software/liblitesdcard/sdcard.c b/litex/soc/software/liblitesdcard/sdcard.c index 1a292970..9c2a5622 100644 --- a/litex/soc/software/liblitesdcard/sdcard.c +++ b/litex/soc/software/liblitesdcard/sdcard.c @@ -26,7 +26,7 @@ #endif #ifndef SDCARD_CLK_FREQ -#define SDCARD_CLK_FREQ 50000000 +#define SDCARD_CLK_FREQ 25000000 #endif unsigned int sdcard_response[SD_CMD_RESPONSE_SIZE/4];