Hi, all
We have just build our 3 custom DM648 boards, we use PCI boot to download the code and boot the device. Right now, we have 2 boards work fine with the PCI, but one other boards dosen't.
By using JTAG after powering up, I found the MDSTAT19 (which is the PCI mega module) is 0x00000A00, which means it is still in the SwRstDisable state, however, MDSTAT8(UHPI) is 0x00001E03(enable).... But accroding to the datasheet, when UHPIEN pin is 0, UHPI is disabled with PCI is enabled! I've checked the BOOTCFG register (0x01990001), UHPIEN is indeed latched with value 0.
Secondly, I try to enable the PCI by hand, with no fortune, I could only successfully changed the UHPI state into swRstDisable state, but could not enable PCI manually. After disable UHPI, by doing
a. check PTSTAT, ok.
b. MDCTL19=0x03
c. PTCMD = 0x01
4. check PTSTAT, ok.
5. MDSTAT19 never changes.. always 0x00000A00, Very strange.
Dose anyone could give some clues on how to debug this, I am really confused and don't know where to start, any suggestions would be very appreciated. Thanks.
FYI:
a. I've test the DDR2, it seems fine on this board
b. when using Lyrtech EVM board, I found with the same boot configuration, the BOOTCFG register is 0x019D0001, differs with our board on bit 18, which is `Reserved` and not documented on datasheets.
