From 6fbf261f8df294e589cfadebebe5468e3c0f29e9 Mon Sep 17 00:00:00 2001 From: Xie Xiaobo Date: Fri, 9 Mar 2007 19:08:25 +0800 Subject: [PATCH] Fix two bugs for MPC83xx DDR2 controller SPD Init There are a few bugs in the cpu/mpc83xx/spd_sdram.c the first bug is that the picos_to_clk routine introduces a huge rounding error in 83xx. the second bug is that the mode register write recovery field is tWR-1, not tWR >> 1. --- cpu/mpc83xx/spd_sdram.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/cpu/mpc83xx/spd_sdram.c b/cpu/mpc83xx/spd_sdram.c index d9b8753..41a1f1f 100644 --- a/cpu/mpc83xx/spd_sdram.c +++ b/cpu/mpc83xx/spd_sdram.c @@ -58,8 +58,8 @@ picos_to_clk(int picos) int clks; ddr_bus_clk = gd->ddr_clk >> 1; - clks = picos / ((1000000000 / ddr_bus_clk) * 1000); - if (picos % ((1000000000 / ddr_bus_clk) * 1000) != 0) + clks = picos / (1000000000 / (ddr_bus_clk / 1000)); + if (picos % (1000000000 / (ddr_bus_clk / 1000)) != 0) clks++; return clks; @@ -624,7 +624,7 @@ long int spd_sdram() | (1 << (16 + 10)) /* DQS Differential disable */ | (add_lat << (16 + 3)) /* Additive Latency in EMRS1 */ | (mode_odt_enable << 16) /* ODT Enable in EMRS1 */ - | ((twr_clk >> 1) << 9) /* Write Recovery Autopre */ + | ((twr_clk - 1) << 9) /* Write Recovery Autopre */ | (caslat << 4) /* caslat */ | (burstlen << 0) /* Burst length */ ); -- 2.7.4