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| author | Stefan Roese <sr@denx.de> | 2006-07-28 18:34:58 +0200 |
|---|---|---|
| committer | Stefan Roese <sr@denx.de> | 2006-07-28 18:34:58 +0200 |
| commit | a2c95a72247990dee9a03b26b4dc9fc0182c97ed (patch) | |
| tree | cabdaa860480f895cccc6600f3454a751329c13c /cpu/ppc4xx | |
| parent | fc6c4a67ae94adac02da6257a0f5adc3bd48ebec (diff) | |
| download | barebox-a2c95a72247990dee9a03b26b4dc9fc0182c97ed.tar.gz barebox-a2c95a72247990dee9a03b26b4dc9fc0182c97ed.tar.xz | |
PPC440 DDR setup: Set SDRAM0_CFG0[PMU]=0 for best performance
AMCC suggested to set the PMU bit to 0 for best performace on
the PPC440 DDR controller.
Please see doc/README.440-DDR-performance for details.
Patch by Stefan Roese, 28 Jul 2006
Diffstat (limited to 'cpu/ppc4xx')
| -rw-r--r-- | cpu/ppc4xx/sdram.c | 2 | ||||
| -rw-r--r-- | cpu/ppc4xx/spd_sdram.c | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/cpu/ppc4xx/sdram.c b/cpu/ppc4xx/sdram.c index e31d59d80e..faeea5c91e 100644 --- a/cpu/ppc4xx/sdram.c +++ b/cpu/ppc4xx/sdram.c @@ -379,7 +379,7 @@ long int initdram(int board_type) /* * Enable the controller, then wait for DCEN to complete */ - mtsdram(mem_cfg0, 0x86000000); /* DCEN=1, PMUD=1, 64-bit */ + mtsdram(mem_cfg0, 0x82000000); /* DCEN=1, PMUD=0, 64-bit */ udelay(10000); if (get_ram_size(0, mb0cf[i].size) == mb0cf[i].size) { diff --git a/cpu/ppc4xx/spd_sdram.c b/cpu/ppc4xx/spd_sdram.c index c0a6933b84..c24456bea8 100644 --- a/cpu/ppc4xx/spd_sdram.c +++ b/cpu/ppc4xx/spd_sdram.c @@ -1007,9 +1007,9 @@ void program_cfg0(unsigned long* dimm_populated, } /* - * program Page Management Unit + * program Page Management Unit (0 == enabled) */ - cfg0 |= SDRAM_CFG0_PMUD; + cfg0 &= ~SDRAM_CFG0_PMUD; /* * program Memory Controller Options 0 |