1) Yes the CYDEV_CHIP_JTAG_ID and CYDEV_CHIP_REV_EXPECT bits holds the silicon ID and revision bytes and is compared with the header record of cyacd file before bootloading.
The header record format:
[4-byte SiliconID][1-byte SiliconRev][1-byte Checksum Type]
I found another register MLOGIC_REV_ID which contains the Silicon Revision ID.
2) Not sure where these registers are defines in TRM
So where can I find the registers for the PSoC3? ..cant seem to find that info anywhere.