Communicating with imx53QSB loco board through flyswatter2

Hello,

I m trying to communicate with imx53 loco board through flyswatter2. I am able to halt, read register values, access internal memory successfully using openocd commands. When I access external RAM (DDR3), I get the below error

mdw 0x70000000 1
Timeout (1000ms) waiting for ACK=OK/FAULT in JTAG-DP transaction - aborting
JTAG-DP OVERRUN - check clock, memaccess, or reduce jtag speed
MEM_AP_CSW 0x28000d2, MEM_AP_TAR 0x70000000
Block read error address 0x70000000
in procedure ‘mdw’

All further access results in throwing,

JTAG-DP STICKY ERROR
MEM_AP_CSW 0x28000d2, MEM_AP_TAR 0x70000000
JTAG-DP STICKY ERROR
MEM_AP_CSW 0x28000d2, MEM_AP_TAR 0x70000000
Block read error address 0x70000000
in procedure ‘mdw’

I also verified the DDR initialization routine, took values from working u-boot but no luck. Can anyone point me to some hints on how to tackle the problem.

Regards,

AB