Fujitsu MB91191 Manuel D’Utilisation
36
CHAPTER 3 CPU
3.4
General-purpose Register
Register R0 to R15 is a general-purpose register. These registers are used as the
pointer for memory access and accumulator for various operations.
pointer for memory access and accumulator for various operations.
■
General-purpose Register
Figure 3.4-1 shows the configuration of the general-purpose register.
Figure 3.4-1 Configuration of general-purpose register
Register R0-R15 is a general register. These registers are used as the pointer for memory access and
accumulator for various operations. The following of the 16 registers are expected to have special uses, so
some commands are emphasized.
•
R13: Virtual accumulator (AC)
•
R14: Frame pointer (FP)
•
R15: Stack pointers (SP)
R0 to R14 of the initial value by reset is irregular. R15 becomes 00000000
H
(value of SSP).
32
bit
[Initial
value]
XXXX
XXXX
H
XXXX
XXXX
H
XXXX
XXXX
H
XXXX
XXXX
H
XXXX XXXX
H
0000 0000
H
AC
R0
R1
R1
R12
R13
R13
R14
R15
FP
SP