Testing other frequencies I noticed that I made a mistake.
The value set by u-boot in "PLL_DDR Control Register" is 1344MHz:
=> md 0x01C20020 1
01c20020: 90001b10
The "DRAM configuration register" has CLK_SRC_SEL set to PLL_DDR
and the divider M set to 1 (DRAM_DIV_M = 0):
=> md 0x01C202F4 1
01c202f4: 00000000
So If I'm not missing something, the clock for dram should be 1344MHz.
The u-boot configuration for this board reads:
CONFIG_DRAM_CLK=672
So it seems that the frequency is doubled. I'll take a look.
The h5 datasheet says that the sdram controller supports up to 667
MHz(DDR3-1333).
The funny thing is that the freq I was setting was 1200MHz, not 576MHz.
I'm testing now with 648MHz, the board is really stable. I'm even
surprised by the performance of iridium with only 1G.
boot.cmd:
============================================================
# PLL_DDR Output = (24MHz*N*K)/M
# Bits to set:
# 31 | PLL_ENABLE.
# 20 | Update, must be set when changing the PLL.
# 12:8 | N - 1.
# 5:4 | K - 1.
# 1:0 | M - 1.
echo Setting DDR3 freq to 648MHz
mw 0x01C20020 0x80101A00
load mmc 0:1 ${fdt_addr_r} ${fdtfile}
load mmc 0:1 ${kernel_addr_r} efi/boot/bootaa64.efi
bootefi ${kernel_addr_r} ${fdt_addr_r}
============================================================
Regards,
adr.
