Hardware/GX/Command Processor

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Command Processor
Access
BroadwayFull
StarletNone
Registers
Base0x0c000000
Length0x80
Access size16 bits
Byte orderBig Endian
IRQs
Broadway11
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The Command Processor is a part of the Wii's GX system, and is responsible for handling all of the commands that draw to the EFB.

CP (command processor) Registers

CP_FIFO_STATUS (0xCC000000)
  15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Access U R R R R R
Field BPInt CmdIdle RdIdle UF OF
Field Description
BPInt Indicates status of Blitting Processor interrupt?
CmdIdle 1: CP is not doing anything
RdIdle 1: CP is not reading anything (??)
UF FIFO underflow (Determined by watermark registers?
OF FIFO overflow ("")

CP_CONTROL (0xCC000002)
  15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Access U R/W R/W R/W R/W R/W R/W
Field BPE GPLE UFInt OFInt CPInt FIFOE
Field Description
BPE breakpoint enable (default 0)
GPLE FIFO link enable (YAGCD says CP->PE?) (default 1)
UFInt FIFO underflow interrupt (default 0)
OFInt FIFO overflow interrupt (default 1)
CPInt Command Processor interrupt (default 0)
FIFOE FIFO read enable (disable while setting up) (default 1)

CP_CLEAR (0xCC000004)
  15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Access U R/W R/W
Field Under Over
Field Description
Under Write 1 to clear FIFO underflow
Over Write 1 to clear FIFO overflow

CP_TOKEN (0xCC00000E)
  150
Access R

This register contains the last token that was read from the FIFO.

CP_FIFO_START (0xCC000020)
  310
Access R/W

WARNING: This CP register is actually two 16 bit registers. Though it is big endian, a bug in the hardware means the two 16 bit halves will be swapped if you write to it 32-bit. You have been warned!

CP_FIFO_END (0xCC000024)
  310
Access R/W

WARNING: This CP register is actually two 16 bit registers. Though it is big endian, a bug in the hardware means the two 16 bit halves will be swapped if you write to it 32-bit. You have been warned!

CP_FIFO_WP (0xCC000034)
  310
Access R/W

WARNING: This CP register is actually two 16 bit registers. Though it is big endian, a bug in the hardware means the two 16 bit halves will be swapped if you write to it 32-bit. You have been warned!

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