Rabbit 2000 - 6. Rabbit Internal I;O Registers; 6.1 Default Values for all the Peripheral Control Registers

User’s Manual 65
6. RABBIT INTERNAL I/O REGISTERS
6.1 Default Values for all the Peripheral Control Registers
The default values for all of the peripheral control registers are shown in Table 6-1. Addi-
tional I/O registers were added in the Rabbit 2000 revisions as listed in the table. Refer to
Section B.2.1 for more information.
The registers within the CPU affected by a reset are the Stack Pointer (SP) register, the Pro-
gram Counter (PC) register, the IIR register, the EIR register, and the IP register. The IP
register is set to all ones (disabling all interrupts), while all of the other listed CPU registers
are reset to all zeros.
Table 6-1. Rabbit Internal I/O Registers
Register Name Mnemonic I/O Address R/W Reset
Data Segment Register (data segment memory
pointer—locates data segment in physical
memory)
DATASEG
(Z180 BBR)
0x12 R/W 00000000
Segment Size Register (specifies start of data
segment and start of stack segment in 64K
memory space)
SEGSIZE
(Z180 CBAR)
0x13 R/W 11111111
Stack Segment Register (stack segment mem-
ory pointer—locates stack segment in physical
memory)
STACKSEG
(Z180 CBR)
0x11 R/W 00000000
Global Control/Status Register (control of
clocks, periodic interrupts, and monitoring of
watchdog)
GCSR 0x0 R/W 11000000
Global Clock Double Register GCDR 0xF W xxxxx000
Global Clock Modulator 0 Register (Rev B–C) GCM0R 0x0A W 00000000
Global Clock Modulator 1 Register (Rev B–C) GCM1R 0x0B W 00000000
Global CPU Configuration Register (Rev A–C) GCPU 0x2E R 0xx00000
Global Output Control Register GOCR 0xE W 00000x00