P3041 DDR Specific FAQs

[#1]

What is requirement for the voltage ripple of DDR3 controller MVref?

The nominal value of MVref is 1.5V. 1%, +/- 7.5mV is the tolerance value for MVref (ripple range).

Can you please explain the RDRVR resistance for DDR3 SDRAM memory interface?

RDRVR is the "Driver" resistance. It is the resistance at the driver side. Half strength is ~40 ohms and full strength is ~20 ohms.

How can I determine the power rating of the resistor connected to MDIC0 and MDIC1 for both half strength and full strength?

The MDIC resistors connected to MDIC [0:1] signals used for either full or half drive strength calibration do not draw much current. So you can use 1/16W rated resistors for either half or full drive calibration.

[t_alex]

Hi,

We are trying to configure DDR3 on our platform from u-boot.

We tried to disable auto calibration at the moment.

After setting D_INIT bit in DDR_DDR_SDRAM_CFG_2, the bit is never cleared to 0.

None if the bit in DDR_ERR_DETECT is set so we do not know what is the actual problem.

Is there any clue?

Below are the u-boot log which indicates more about CPU version. I am not sure about which erratum we need to enable as well.

-----------------

UBoot 2013.01QorIQ-SDK-V1.5 (May 20 2014 - 11:25:39)

CPU0:  P3041, Version: 1.1, (0x82110311)

Core:  E500MC, Version: 2.2, (0x80230022)

Clock Configuration:

       CPU0:1200 MHz, CPU1:1200 MHz, CPU2:1200 MHz, CPU3:1200 MHz,

       CCB:900  MHz,

       DDR:650  MHz (1300 MT/s data rate) (Asynchronous), LBC:112.500 MHz

       FMAN1: 450 MHz

       QMAN:  450 MHz

       PME:   450 MHz

L1:    D-cache 32 kB enabled

       I-cache 32 kB enabled

Reset Configuration Word (RCW):

       00000000: 125a0000 00000000 18180000 00000000

       00000010: d8404a3f ffc02000 58000000 01000000

       00000020: 00200000 00000000 00000000 ccd80ef7

       00000030: a0000000 00000000 00000000 00000000

Board: P3041 Custom board

I2C:   ready

DRAM:  Initializing....using fixed parameters

Configuring DDR for 1300 MT/s data rate

Workaround for ERRATUM_DDR_A003

total 2 GB

Need to wait up to 40 * 10ms

Waiting for D_INIT timeout. Memory may not work.

2 GiB (DDR3, 64-bit, CL=11, ECC off)

---------------

[itsme]

Hi t-alex,

I just got my new board and I have the same error "waiting for D_INIT timeout" with P2041.  Do you have a solution for it if you can share?  Thx