projects / litex.git / commitdiff
? search:
summary | shortlog | log | commit | commitdiff | tree
raw | patch | inline | side by side (parent: 2d9dc8f)
liblitesdcard/sdcard: (temporarily) slow down SDCARD_CLK_FREQ to 25MHz
authorGabriel Somlo <gsomlo@gmail.com>
Mon, 3 Aug 2020 16:03:39 +0000 (12:03 -0400)
committerGabriel Somlo <gsomlo@gmail.com>
Mon, 3 Aug 2020 20:14:11 +0000 (16:14 -0400)
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 <gsomlo@gmail.com>
litex/soc/software/liblitesdcard/sdcard.c patch | blob | history

diff --git a/litex/soc/software/liblitesdcard/sdcard.c b/litex/soc/software/liblitesdcard/sdcard.c
index 1a2929700c7c9a7e29589d47bb3c9cd0370d8bc6..9c2a56228268711babde945f637f36a9fae8eba4 100644 (file)
--- 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];