AnsweredAssumed Answered

Bring-up issue at 1000 MHz. Works fine at 800 MHz

Question asked by Artem Epishkin on Dec 5, 2016


We are bringing up out custom board with ls1020a (rev 2) processor. We managed to successfully run u-boot and Linux at 800 MHz. Clock frequency of 1 GHz is what we are currently having trouble with. Our board can successfully load RCW from QSPI-Flash and perform power-on-reset sequence but then something goes wrong. The only difference between 800 MHz and 1 GHz configurations in our case is the CGA_PLL1_RAT field of the RCW. The cfg_rcw_src is set to 0x45 with resistors.

Some thing we've already tried:
1. Programming QSPI-Flash with hard-coded RCWs using an external programmer and then booting from it. Both 9C and 9E pass power-on-reset (judging by ASLEEP pin). Then we try to download a basic project via JTAG and CodeWarrior. The download is successful for 9C but fails with "Can't connect to CCS" for 9E.
2. JTAG RCW override. We can successfully load and debug a basic project at 1 GHz if the cpu is told to use 9E in the JTAG configuration file.
3. CCS utility allows us to read registers even when cpu fails to boot at 1 GHz. We examined the contents of DCFG_CCSR registers and found nothing suspicious or helpful there.

Is there anything else we can try from the software side in order to diagnose this issue?

Original Attachment has been moved to: