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From: Kumar Gala <galak@kernel.crashing.org>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] fsl-ddr: Add extra cycle to turnaround times
Date: Wed,  7 Apr 2010 12:34:31 -0500	[thread overview]
Message-ID: <1270661671-28405-5-git-send-email-galak@kernel.crashing.org> (raw)
In-Reply-To: <1270661671-28405-4-git-send-email-galak@kernel.crashing.org>

From: Dave Liu <daveliu@freescale.com>

Add an extra cycle turnaround time to read->write to ensure stability
at high DDR frequencies.

Signed-off-by: Dave Liu <daveliu@freescale.com>
---
 cpu/mpc8xxx/ddr/ctrl_regs.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/cpu/mpc8xxx/ddr/ctrl_regs.c b/cpu/mpc8xxx/ddr/ctrl_regs.c
index 03f9c43..4a282bc 100644
--- a/cpu/mpc8xxx/ddr/ctrl_regs.c
+++ b/cpu/mpc8xxx/ddr/ctrl_regs.c
@@ -198,6 +198,8 @@ static void set_timing_cfg_0(fsl_ddr_cfg_regs_t *ddr)
 	pre_pd_exit_mclk = act_pd_exit_mclk;
 	taxpd_mclk = 8;
 	tmrd_mclk = 4;
+	/* set the turnaround time */
+	trwt_mclk = 1;
 #else /* CONFIG_FSL_DDR2 */
 	/*
 	 * (tXARD and tXARDS). Empirical?
-- 
1.6.0.6

      reply	other threads:[~2010-04-07 17:34 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-07 17:34 [U-Boot] [PATCH] ppc/p4080: Fix synchronous frequency calculations Kumar Gala
2010-04-07 17:34 ` [U-Boot] [PATCH] ppc/p4080: Extend the GUTS memory map Kumar Gala
2010-04-07 17:34   ` [U-Boot] [PATCH] ppc/p4080: Add p4080 DEVDISR2 & SRDS_PLLCR0 defines Kumar Gala
2010-04-07 17:34     ` [U-Boot] [PATCH] fsl-ddr: add the macro for Rtt_Nom definition Kumar Gala
2010-04-07 17:34       ` Kumar Gala [this message]

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