MC68HC705J1ACPE Datasheet, PDF (50/162 Pages) Freescale Semiconductor, Inc – Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.
Central Processor Unit (CPU)
3.5.4 Program Counter
The program counter (PC) is a 16-bit register that contains the address
of the next instruction or operand to be fetched. The five most significant
bits of the program counter are ignored and appear as 00000.
Normally, the address in the program counter automatically increments
to the next sequential memory location every time an instruction or
operand is fetched. Jump, branch, and interrupt operations load the
program counter with an address other than that of the next sequential
location.
Bit
Bit
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Read:
Write:
Reset: 0 0 0 0 0
Loaded with vector from $07FE and $07FF
Figure 3-5. Program Counter (PC)
3.5.5 Condition Code Register
The condition code register (CCR) is an 8-bit register whose three most
significant bits are permanently fixed at 111. The condition code register
contains the interrupt mask and four flags that indicate the results of the
instruction just executed.
Bit 7
6
5
4
3
2
1
Bit 0
Read: 1
1
1
H
I
N
Z
C
Write:
Reset: 1
1
1
U
1
U
U
U
= Unimplemented
U = Unaffected
Figure 3-6. Condition Code Register (CCR)
Technical Data
MC68HC705J1A — Rev. 4.0
Central Processor Unit (CPU)
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