ppc4xx: Fixed offset of refresh rate type for Bamboo on-board DDR SDRAM

This patch also adds a note to the fixed DDR setup for Bamboo NAND booting:

Note:
As found out by Eugene O'Brien <eugene.obrien@advantechamt.com>, the fixed
DDR setup has problems (U-Boot crashes randomly upon TFTP), when the DIMM
modules are still plugged in. So it is recommended to remove the DIMM
modules while using the NAND booting code with the fixed SDRAM setup!

Signed-off-by: Eugene O'Brien <eugene.obrien@advantechamt.com>
Signed-off-by: Stefan Roese <sr@denx.de>
This commit is contained in:
Eugene O'Brien 2007-10-23 08:29:10 +02:00 committed by Stefan Roese
parent afe9fa59cb
commit 9f798766aa
2 changed files with 8 additions and 2 deletions

View File

@ -67,13 +67,13 @@ const unsigned char cfg_simulate_spd_eeprom[128] = {
0x00, /* Module data width continued: +0 */
0x04, /* 2.5 Volt */
0x75, /* SDRAM Cycle Time (cas latency 2.5) = 7.5 ns */
0x00, /* SDRAM Access from clock */
#ifdef CONFIG_DDR_ECC
0x02, /* ECC ON : 02 OFF : 00 */
#else
0x00, /* ECC ON : 02 OFF : 00 */
#endif
0x82, /* refresh Rate Type: Normal (15.625us) + Self refresh */
0,
0x82, /* refresh Rate Type: Normal (7.8us) + Self refresh */
0,
0,
0x01, /* wcsbc = 1 */

View File

@ -44,6 +44,12 @@ static void wait_init_complete(void)
* not enough free space to implement the complete I2C SPD DDR autodetection
* routines. Therefore the Bamboo only supports the onboard 64MBytes of SDRAM
* when booting from NAND flash.
*
* Note:
* As found out by Eugene O'Brien <eugene.obrien@advantechamt.com>, the fixed
* DDR setup has problems (U-Boot crashes randomly upon TFTP), when the DIMM
* modules are still plugged in. So it is recommended to remove the DIMM
* modules while using the NAND booting code with the fixed SDRAM setup!
*/
void early_sdram_init(void)
{