Dear all,
i'm working on a custom DM3730 board equipped with a 256MB LPDDR1 from Micron, 166MHz,
PN: MT46H64M32LFCM-6 IT:A
I set the controller to 166 MHz using x-loader from arago, with the following instruction set:
/* reset sdrc controller */
__raw_writel(SOFTRESET, SDRC_SYSCONFIG);
wait_on_value(BIT0, BIT0, SDRC_STATUS, 12000000);
__raw_writel(0, SDRC_SYSCONFIG);
/* setup sdrc to ball mux */
__raw_writel(SDP_SDRC_SHARING, SDRC_SHARING);
__raw_writel(0x2, SDRC_CS_CFG); /* 256MB/bank */
__raw_writel(SDP_SDRC_MDCFG_0_DDR_XM, SDRC_MCFG_0);
__raw_writel(SDP_SDRC_MDCFG_0_DDR_XM, SDRC_MCFG_1);
__raw_writel(MICRON_V_ACTIMA_165, SDRC_ACTIM_CTRLA_0);
__raw_writel(MICRON_V_ACTIMB_165, SDRC_ACTIM_CTRLB_0);
__raw_writel(MICRON_V_ACTIMA_165, SDRC_ACTIM_CTRLA_1);
__raw_writel(MICRON_V_ACTIMB_165, SDRC_ACTIM_CTRLB_1);
__raw_writel(SDP_3430_SDRC_RFR_CTRL_165MHz, SDRC_RFR_CTRL_0);
__raw_writel(SDP_3430_SDRC_RFR_CTRL_165MHz, SDRC_RFR_CTRL_1);
__raw_writel(SDP_SDRC_POWER_POP, SDRC_POWER);
/* init sequence for mDDR/mSDR using manual commands (DDR is different) */
__raw_writel(CMD_NOP, SDRC_MANUAL_0);
__raw_writel(CMD_NOP, SDRC_MANUAL_1);
delay(5000);
__raw_writel(CMD_PRECHARGE, SDRC_MANUAL_0);
__raw_writel(CMD_PRECHARGE, SDRC_MANUAL_1);
__raw_writel(CMD_AUTOREFRESH, SDRC_MANUAL_0);
__raw_writel(CMD_AUTOREFRESH, SDRC_MANUAL_1);
__raw_writel(CMD_AUTOREFRESH, SDRC_MANUAL_0);
__raw_writel(CMD_AUTOREFRESH, SDRC_MANUAL_1);
/* set mr0 */
__raw_writel(SDP_SDRC_MR_0_DDR, SDRC_MR_0);
__raw_writel(SDP_SDRC_MR_0_DDR, SDRC_MR_1);
/* set up dll */
__raw_writel(SDP_SDRC_DLLAB_CTRL, SDRC_DLLA_CTRL);
delay(0x2000); /* give time to lock */
with a probe I see a 200MHz clock, instead of 166, as expected.
My system often hangs, probably due to the SDRAM over clocking.
What is the correct way to set 166Mhz SDRC clock?
Andrea
