256MB Micron Low Power DDR register configuration

Lorenzo Salvadori

Other Parts Discussed in Thread: AM3703, SYSCONFIG

Hi all,

I'm trying to configure memory LPDDR on a processor AM3703 sitara. The memory is:

MICRON Mobile256MB Low-Power DDR SDRAM MT40H256M32L4 AND THE CLOCK RATE IS 166MHz.

Is something wrong in my SDRC register configuration?? my kernel crash if I try to reserve more than 128Mbyte in my bootargs arguments

SDRC_SYSCONFIG            0x0010
SDRC_CS_CFG                    0x0002
SDRC_SHARING                  0x0100
SDRC_ERR_TYPE               0x0008
SDRC_DLLA_CTRL            0x000A
SDRC_DLLA_STATUSL       0x0004
SDRC_DLLB_CTRL            0x0000
SDRC_DLLB_STATUS        0x0000
SDRC_POWER                     0x0001
SDRC_MCFG_0                    0x3588099
SDRC_MR_0                   0x0032
SDRC_EMR2_0            0x0000
SSDRC_ACTIM_CTRL_A_0    0x92E1C4C6
SDRC_ACTIM_CTRL_B_0       0x2111C
SDRC_RFR_CTRL_0               0x4DC01
SDRC_MANUAL_0              0x0002
SDRC_MCFG_1            0x2584099
SDRC_MR_1                   0x0032
SDRC_EMR2_1            0x0000
SDRC_ACTIM_CTRL_A_1    0xAA9DB4C6
SDRC_ACTIM_CTRL_B_1    0x11517
SDRC_RFR_CTRL_1             0x4E201
SDRC_MANUAL_1              0x0002

thanks in advance

over 12 years ago

0 Biser Gatchev-XID over 12 years ago

TI__Guru**** 393215 points

Hi Lorenzo,

Have you seen this: http://processors.wiki.ti.com/index.php/Setting_up_AM37x_SDRC_registers

0 Lorenzo Salvadori over 12 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

Hi Biser,

following your advice I have used the tool to calculate the timings and I modified the following registers in the X-loader:

SDRC_ACTIM_CTRLA_1 = 0x62a9b4c5

SDRC_ACTIM_CTRLB_1 = 0x21213

SDRC_RFR_CTRL_1 = 0x4e201

I checked doing a print in the kernel that the changes have taken effect, but the system keeps crashing using more than 128Mb of RAM.

thanks, Lorenzo

0 Biser Gatchev-XID over 12 years ago in reply to Lorenzo Salvadori

TI__Guru**** 393215 points

Can you give the exact part number of your LPDDR memory? I suspect it's a dual-die or quad-die memory. Do you have both CS0/1# and CKE0/1 signal connected to the memory?

0 Lorenzo Salvadori over 12 years ago in reply to Biser Gatchev-XID

Prodigy 130 points

The part Number of Low power DDR is MT46H64M32LFCX and I have only CS0 and CKE0 connected to the memory

0 Biser Gatchev-XID over 12 years ago in reply to Lorenzo Salvadori

TI__Guru**** 393215 points

That's allright then, this one has only one CS and CKE.

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256MB Micron Low Power DDR register configuration