MC68HC908JG16 Datasheet, PDF (75/324 Pages) Motorola, Inc – Microcontrollers

Central Processor Unit (CPU)
CPU Registers
6.4 CPU Registers
Figure 6-1 shows the five CPU registers. CPU registers are not part of
the memory map.
15
H
15
15
7
0
ACCUMULATOR (A)
0
X
INDEX REGISTER (H:X)
0
STACK POINTER (SP)
0
PROGRAM COUNTER (PC)
7
0
V 1 1 H I N Z C CONDITION CODE REGISTER (CCR)
CARRY/BORROW FLAG
ZERO FLAG
NEGATIVE FLAG
INTERRUPT MASK
HALF-CARRY FLAG
TWO’S COMPLEMENT OVERFLOW FLAG
Figure 6-1. CPU Registers
6.4.1 Accumulator
The accumulator is a general-purpose 8-bit register. The CPU uses the
accumulator to hold operands and the results of arithmetic/logic
operations.
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
Unaffected by reset
Figure 6-2. Accumulator (A)
1
Bit 0
MC68HC908JG16 — Rev. 1.1
Freescale Semiconductor
Central Processor Unit (CPU)
Technical Data
75