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HARDWARE CONFIGURATION
2-6
CPU
Internal Registers in CPU
The MB89140 series of microcontrollers have dedicated registers in the
CPU and general-purpose registers in memory.
•
Program
counter
(PC)
16-bit long register indicating location
where instructions stored
•
Accumulator (A)
16-bit long register where results of opera-
tions stored temporarily; the lower byte is
used to execute 8-bit data processing
instructions.
•
Temporary accumulator (T)
16-bit long register; the operations are per-
formed between this register and the accu-
mulator. The lower one byte is used to
execute 8-bit data processing instructions
•
Stack pointer (SP)
16-bit long register indicating stack area
•
Processor status (PS)
16-bit long register where register pointers
and condition codes stored
•
Index register (IX)
16-bit long register for index modification
•
Extra pointer (EP)
16-bit long register for memory addressing
P C
A
T
IX
EP
SP
PS
16 bits
Program counter
Accumulator
Temporary accumulator
Index register
Extra pointer
Stack pointer
Processor status
The 16 bits of the processor status (PS) can be divided into 8 upper bits for a
register bank pointer (RP) and 8 lower bits for a condition code register
(CCR). (See Figure 2.4.)
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
PS
RP
Vacant Vacant Vacant
H
I
N
Z
V
C
IL1, 0
RP
CCR
Fig. 2.4 Structure of Processor Status
Содержание F2MC-8L Series
Страница 121: ...INSTRUCTIONS 4 7 4 5 F2MC 8L FAMILY INSTRUCTION MAP ...
Страница 123: ...5 MASK OPTIONS ...
Страница 125: ...APPENDIX ...