MB89PV890CH View Datasheet(PDF) - Fujitsu
Part Name
Description
MFG CO.
'MB89PV890CH' PDF : 51 Pages View PDF
MB89890 Series
2. Registers
The F2MC-8L family has two types of registers; dedicated hardware registers in the CPU and general-purpose
memory registers. The following dedicated registers are provided:
Program counter (PC):
A 16-bit-long register for indicating the instruction storage positions
Accumulator (A):
A 16-bit-long temporary register for arithmetic operations, etc. When the
instruction is an 8-bit data processing instruction, the lower byte is used.
Temporary accumulator (T): A 16-bit-long register which is used for arithmetic operations with the accumulator
When the instruction is an 8-bit data processing instruction, the lower byte is used.
Index register (IX):
A 16-bit-long register for index modification
Extra pointer (EP) :
A 16-bit-long pointer for indicating a memory address
Stack pointer (SP) :
A 16-bit-long pointer for indicating a stack area
Program status (PS) :
A 16-bit-long register for storing a register pointer, a condition code
16 bits
PC
A
T
IX
EP
SP
PS
Initial value
: Program counter
FFFDH
: Accumulator
indeterminate
: Temporary accumulator indeterminate
: Index register
indeterminate
: Extra pointer
indeterminate
: Stack pointer
indeterminate
: Program status
I-flag = 0, IL1, 0 = 11
The other bit values are indeterminate.
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
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
PS
RP
Vacancy Vacancy Vacancy H I
IL1, 0
NZVC
RP
CCR
18
Share Link: 
