MB89656AR FUJITSU [Fujitsu Component Limited.], MB89656AR Datasheet - Page 21

• Manufacturer Part Number: MB89656AR
• Description: 8-bit Proprietary Microcontroller
• Manufacturer: FUJITSU [Fujitsu Component Limited.]

2. Registers
The F
in the memory. The following dedicated registers are provided:
Program counter (PC):
Accumulator (A):
Temporary accumulator (T): A 16-bit register which performs arithmetic operations with the accumulator
Index register (IX):
Extra pointer (EP):
Stack pointer (SP):
Program status (PS):
The PS can further be divided into higher 8 bits for use as a register bank pointer (RP) and the lower 8 bits for
use as a condition code register (CCR). (See the diagram below.)
Structure of the Program Status Register
2
MC-8L family has two types of registers; dedicated registers in the CPU and general-purpose registers
PS
15
14
RP
13
A 16-bit register for indicating instruction storage positions
A 16-bit temporary register for storing arithmetic operations, etc. When the
instruction is an 8-bit data processing instruction, the lower byte is used.
When the instruction is an 8-bit data processing instruction, the lower byte is used.
A 16-bit register for index modification
A 16-bit pointer for indicating a memory address
A 16-bit register for indicating a stack area
A 16-bit register for storing a register pointer, a condition code
16 bits
PC
EP
SP
PS
IX
A
T
12
RP
11
Vacancy
10
Vacancy Vacancy
9
: Program counter
: Accumulator
: Temporary accumulator
: Index register
: Extra pointer
: Stack pointer
: Program status
8
H
7
6
I
MB89650AR Series
I-flag = 0, IL1, 0 = 11
Other bits are undefined.
5
IL1, 0
Undefined
Undefined
Undefined
Undefined
Undefined
Initial value
FFFD
4
CCR
H
N
3
2
Z
V
1
C
0
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