MC68HC705J MOTOROLA [Motorola, Inc], MC68HC705J Datasheet - Page 50

• Manufacturer Part Number: MC68HC705J
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

Central Processor Unit (CPU)
3.5.4 Program Counter
3.5.5 Condition Code Register
Technical Data
50
Reset:
Read:
Write:
Reset:
Read:
Write:
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.
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
15
Bit 7
0
1
1
14
0
Figure 3-6. Condition Code Register (CCR)
Central Processor Unit (CPU)
= Unimplemented
13
0
6
1
1
Figure 3-5. Program Counter (PC)
12
0
11
0
5
1
1
10
9
Loaded with vector from $07FE and $07FF
H
U
4
8
U = Unaffected
7
3
1
I
6
MC68HC705J1A — Rev. 4.0
5
N
U
2
4
3
U
Z
1
2
MOTOROLA
1
Bit 0
C
U
Bit
0