All registers are 16-bit only. All bits are in little-endian format (mask for bit 0 is 0x0001). CP_SR - Command Processor Status Register [CC000000] R bit 0 : fifo overflow (wrptr > hiWatermark) bit 1 : fifo underlow (rdptr > loWatermark) bit 2 : GP is idle for reading (1 : idle) bit 3 : GP is idle for commands (1 : idle) bit 4 : breakpoint interrupt (other bits are reserved) CP_CR - Command Processor Control Register [CC000002] R/W bit 0 : enable reading of fifo by GP bit 1 : write 1, to clear breakpoint interrupt ? bit 2 : enable overflow checks (high watermark) bit 3 : enable underlow checks (low watermark) bit 4 : link GP and CPU fifos bit 5 : enable breakpoint checks ? (other bits are reserved) CP_CLR - Command Processor Clear Register [CC000004] W bit 0 : write 1, to clear fifo overflow bit 1 : write 1, to clear fifo underlow (other bits are reserved) CP_BASEL [CC000020] R/W CP_BASEH [CC000022] R/W fifo base physical address CP_TOPL [CC000024] R/W CP_TOPH [CC000026] R/W fifo top physical address CP_HIWMARKL [CC000028] R/W CP_HIWMARKH [CC00002A] R/W high watermark physical address CP_LOWMARKL [CC00002C] R/W CP_LOWMARKH [CC00002E] R/W low watermark physical address CP_CNTL [CC000030] R/W CP_CNTH [CC000032] R/W distance between read and write pointers (count) CP_WRPTRL [CC000034] R/W CP_WRPTRH [CC000036] R/W GP fifo write pointer (physical address) CP_RDPTRL [CC000038] R/W CP_RDPTRH [CC00003A] R/W GP fifo read pointer (physical address) CP_BPPTRL [CC00003C] R/W CP_BPPTRH [CC00003E] R/W GP fifo breakpoint (physical address)