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authorHaavard Skinnemoen <hskinnemoen@atmel.com>2008-01-23 17:20:14 +0100
committerHaavard Skinnemoen <hskinnemoen@atmel.com>2008-02-05 12:14:27 +0100
commitd38da537943cd36356b9d3d9d9b60533554b81d8 (patch)
tree6263c715346047e4cda757dff839f4e1052652b7 /cpu/at32ap
parent61151cccb660cdb06a07fb283de6089913d7bde0 (diff)
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AVR32: Make SDRAM refresh rate configurable
The existing code assumes the SDRAM row refresh period should always be 15.6 us. This is not always true, and indeed on the ATNGW100, the refresh rate should really be 7.81 us. Add a refresh_period member to struct sdram_info and initialize it properly for both ATSTK1000 and ATNGW100. Out-of-tree boards will panic() until the refresh_period member is updated properly. Big thanks to Gerhard Berghofer for pointing out this issue. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Diffstat (limited to 'cpu/at32ap')
-rw-r--r--cpu/at32ap/hsdramc.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/cpu/at32ap/hsdramc.c b/cpu/at32ap/hsdramc.c
index a936e03..1fcfe75 100644
--- a/cpu/at32ap/hsdramc.c
+++ b/cpu/at32ap/hsdramc.c
@@ -38,6 +38,10 @@ unsigned long sdram_init(const struct sdram_info *info)
unsigned long bus_hz;
unsigned int i;
+ if (!info->refresh_period)
+ panic("ERROR: SDRAM refresh period == 0. "
+ "Please update the board code\n");
+
tmp = (HSDRAMC1_BF(NC, info->col_bits - 8)
| HSDRAMC1_BF(NR, info->row_bits - 11)
| HSDRAMC1_BF(NB, info->bank_bits - 1)
@@ -113,7 +117,7 @@ unsigned long sdram_init(const struct sdram_info *info)
* 15.6 us is a typical value for a burst of length one
*/
bus_hz = get_sdram_clk_rate();
- hsdramc1_writel(TR, (156 * (bus_hz / 1000)) / 10000);
+ hsdramc1_writel(TR, info->refresh_period);
printf("SDRAM: %u MB at address 0x%08lx\n",
sdram_size >> 20, info->phys_addr);