From 782711e5a9d5d6c8f9988ec8fe8a38f1b5bf4176 Mon Sep 17 00:00:00 2001 From: Chris Ballance Date: Fri, 12 Jan 2018 19:23:08 +0100 Subject: [PATCH] bios/sdram: make read leveling robust for KUS SDRAM Increases the initial delay step into the valid read window as with the original delay I was not getting out of the noisy transition window, as evidenced by seeing read delay windows of only 8 LSB ~10% of the time, leading to failing memory tests --- litex/soc/software/bios/sdram.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/litex/soc/software/bios/sdram.c b/litex/soc/software/bios/sdram.c index d9e3023d0..5b1ebd701 100644 --- a/litex/soc/software/bios/sdram.c +++ b/litex/soc/software/bios/sdram.c @@ -383,7 +383,7 @@ static void read_delays(void) /* Get a bit further into the working zone */ #ifdef KUSDDRPHY - for(j=0;j<8;j++) { + for(j=0;j<16;j++) { delay += 1; ddrphy_rdly_dq_inc_write(1); }