Rabbit Rabbit 4000, User Manual

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Chapter 4 System Management 39
Global Output Control Register (GOCR) (Address = 0x000E)
Bit(s) Value Description
7:6 00 CLK pin is driven with peripheral clock.
01 CLK pin is driven with peripheral clock divided by 2.
10 CLK pin is low.
11 CLK pin is high.
5:4 00 STATUS pin is active (low) during a first opcode byte fetch.
01 STATUS pin is active (low) during an interrupt acknowledge.
10 STATUS pin is low.
11 STATUS pin is high.
3:2 00 /WDTOUT pin functions normally.
01 Enable /WDTOUT for test mode. Rabbit Semiconductor internal use only.
10 /WDTOUT pin is low (1 cycle min, 2 cycles max, of 32 kHz).
11 This bit combination is reserved and should not be used.
1:0 00 /BUFEN pin is active (low) during external I/O cycles.
01 /BUFEN pin is active (low) during data memory accesses.
10 /BUFEN pin is low.
11 /BUFEN pin is high.
Global CPU Register (GCPU) (Address = 0x002E)
Bit(s) Value Description
7 0 Program fetch as a function of the SMODE pins.
(read only) 1 Ignore the SMODE pins program fetch function.
6:5 read These bits report the state of the SMODE pins.
4:0 00010 CPU identifier for this version of the chip.
Global Revision Register (GREV) (Address = 0x002F)
Bit(s) Value Description
7 0 Program fetch as a function of the SMODE pins.
(read only) 1 Ignore the SMODE pins program fetch function.
6:5 read These bits report the state of the SMODE pins.
4:0 00000 Revision identifier for this version of the chip.