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From: Valentin Longchamp <valentin.longchamp@keymile.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 10/17] powerpc/km8321: set the DDRCDR impedance settings back to half strength
Date: Fri, 13 Nov 2015 15:59:21 +0100	[thread overview]
Message-ID: <1447426768-23226-11-git-send-email-valentin.longchamp@keymile.com> (raw)
In-Reply-To: <1447426768-23226-1-git-send-email-valentin.longchamp@keymile.com>

The impedance settings have been changed with commit
2ea8ae99595ca11dd228726e854ebc6268208601 (whose goal was to set
the internal voltage level to the DDR2 value - and not DDR1).

There was no other good reason to set them to nominal strength than
"the others do it like that" according to Ludger. The others however
very often use DIMM modules where the nominal strength makes sense.

In our case where the DRAM chips are soldered on board and the routing
for these signals under control, half-strength is sufficient as a few
measurements done in the lasts have shown. Since all the hardware
qualification tests have been performed with half strength, the nominal
strength settings are removed in favor of the default reset half
strength settings.

Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
---

 include/configs/km/km8321-common.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/configs/km/km8321-common.h b/include/configs/km/km8321-common.h
index 6f21c05..b2e68e3 100644
--- a/include/configs/km/km8321-common.h
+++ b/include/configs/km/km8321-common.h
@@ -67,8 +67,8 @@
 
 #define CONFIG_SYS_DDRCDR (\
 	DDRCDR_EN | \
-	DDRCDR_PZ_NOMZ | \
-	DDRCDR_NZ_NOMZ | \
+	DDRCDR_PZ_MAXZ | \
+	DDRCDR_NZ_MAXZ | \
 	DDRCDR_M_ODR)
 
 #define CONFIG_SYS_DDR_CS0_BNDS		0x0000007f
-- 
1.8.3.1

  parent reply	other threads:[~2015-11-13 14:59 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-13 14:59 [U-Boot] [PATCH 00/17] km/powerpc: various bugfixes and support for 3 new boards Valentin Longchamp
2015-11-13 14:59 ` [U-Boot] [PATCH 01/17] powerpc/83xx/km: add support for kmvect1 p1a hw version Valentin Longchamp
2015-11-16 10:01   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 02/17] powerpc/83xx: add support for kmtepr2 board Valentin Longchamp
2015-11-16 10:01   ` Heiko Schocher
2015-11-16 12:18   ` Holger Brunck
2015-11-13 14:59 ` [U-Boot] [PATCH 03/17] powerpc/82xx: make set/get_pin for km82xx more flexible Valentin Longchamp
2015-11-16 10:06   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 04/17] powerpc/82xx/km: add testpin detection for mgcoge3ne Valentin Longchamp
2015-11-16 10:58   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 05/17] km/powerpc: increase space for kernel imange and FDT blob Valentin Longchamp
2015-11-16 10:58   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 06/17] km/powerpc: move open firmware defines to km-powerpc.h Valentin Longchamp
2015-11-16 10:59   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 07/17] km/powerpc: remove unneeded defines Valentin Longchamp
2015-11-16 11:00   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 08/17] km/powerpc82xx: remove unused function Valentin Longchamp
2015-11-16 11:01   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 09/17] powerpc/km8321: define CONFIG_SYS_DDRCDR Valentin Longchamp
2015-11-16 11:02   ` Heiko Schocher
2015-11-13 14:59 ` Valentin Longchamp [this message]
2015-11-16 11:02   ` [U-Boot] [PATCH 10/17] powerpc/km8321: set the DDRCDR impedance settings back to half strength Heiko Schocher
2015-11-16 12:26   ` Holger Brunck
2015-11-16 13:34     ` Tom Rini
2015-11-16 15:41       ` Valentin Longchamp
2015-11-13 14:59 ` [U-Boot] [PATCH 11/17] powerpc/km8309: define CONFIG_SYS_DDRCDR Valentin Longchamp
2015-11-16 11:03   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 12/17] powerpc/km8360: fix the ODT parameters for CS0 Valentin Longchamp
2015-11-16 11:03   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 13/17] board/keymile/km82xx: setting dip_switch 3 and 4 will run bootloader Valentin Longchamp
2015-11-16 11:04   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 14/17] km83xx: use CONFIG_ENV_ADDR for the newenv env command Valentin Longchamp
2015-11-16 11:05   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 15/17] km8309: change the default QE_FW address Valentin Longchamp
2015-11-16 11:05   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 16/17] powerpc/83xx: add support for kmtegr1 board Valentin Longchamp
2015-11-16 11:06   ` Heiko Schocher
2015-11-13 14:59 ` [U-Boot] [PATCH 17/17] km/powerpc: fix ft_board_setup prototype for km82xx & km83xx Valentin Longchamp
2015-11-16 11:07   ` Heiko Schocher

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