From: Howard Gregory Date: Tue, 4 Nov 2008 06:55:33 +0000 (+0800) Subject: mpc83xx: Improve the performance of DDR memory X-Git-Tag: v2009.01-rc1~64^2~1 X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=2f2a5c3714d17f4ead18b713128b7226e0e822f4;p=u-boot mpc83xx: Improve the performance of DDR memory modify the CAS timings. my understanding is that these settings decrease various wait times in the DDR interface. Because these wait times are in clock cycles, and the DDR clock on the 8315 RDB runs slower than on some other 83xx platforms, we can dial down these values without a problem, thereby decreasing the latency of memory a little. Signed-off-by: Howard Gregory Signed-off-by: Dave Liu Signed-off-by: Kim Phillips --- diff --git a/include/configs/MPC8315ERDB.h b/include/configs/MPC8315ERDB.h index 1225270ffb..add65f03d0 100644 --- a/include/configs/MPC8315ERDB.h +++ b/include/configs/MPC8315ERDB.h @@ -118,23 +118,23 @@ | ( 8 << TIMING_CFG0_ODT_PD_EXIT_SHIFT ) \ | ( 2 << TIMING_CFG0_MRS_CYC_SHIFT ) ) /* 0x00220802 */ -#define CONFIG_SYS_DDR_TIMING_1 ( ( 3 << TIMING_CFG1_PRETOACT_SHIFT ) \ - | ( 9 << TIMING_CFG1_ACTTOPRE_SHIFT ) \ - | ( 3 << TIMING_CFG1_ACTTORW_SHIFT ) \ +#define CONFIG_SYS_DDR_TIMING_1 ( ( 2 << TIMING_CFG1_PRETOACT_SHIFT ) \ + | ( 7 << TIMING_CFG1_ACTTOPRE_SHIFT ) \ + | ( 2 << TIMING_CFG1_ACTTORW_SHIFT ) \ | ( 5 << TIMING_CFG1_CASLAT_SHIFT ) \ | ( 6 << TIMING_CFG1_REFREC_SHIFT ) \ | ( 2 << TIMING_CFG1_WRREC_SHIFT ) \ | ( 2 << TIMING_CFG1_ACTTOACT_SHIFT ) \ | ( 2 << TIMING_CFG1_WRTORD_SHIFT ) ) - /* 0x39356222 */ + /* 0x27256222 */ #define CONFIG_SYS_DDR_TIMING_2 ( ( 1 << TIMING_CFG2_ADD_LAT_SHIFT ) \ | ( 4 << TIMING_CFG2_CPO_SHIFT ) \ | ( 2 << TIMING_CFG2_WR_LAT_DELAY_SHIFT ) \ | ( 2 << TIMING_CFG2_RD_TO_PRE_SHIFT ) \ | ( 2 << TIMING_CFG2_WR_DATA_DELAY_SHIFT ) \ | ( 3 << TIMING_CFG2_CKE_PLS_SHIFT ) \ - | ( 7 << TIMING_CFG2_FOUR_ACT_SHIFT) ) - /* 0x121048c7 */ + | ( 5 << TIMING_CFG2_FOUR_ACT_SHIFT) ) + /* 0x121048c5 */ #define CONFIG_SYS_DDR_INTERVAL ( ( 0x0360 << SDRAM_INTERVAL_REFINT_SHIFT ) \ | ( 0x0100 << SDRAM_INTERVAL_BSTOPRE_SHIFT ) ) /* 0x03600100 */