Fujitsu MB90895 Series Hardware Manual page 67

I Register Bank
The register bank can be used as a general-purpose register (byte registers R0 to R7, word registers RW0 to
RW7, and long-word registers RL0 to RL3) to perform various operations or to serve as a pointer. The
long- word register can also be used as a linear addressing to directly access the entire memory space.
In the same way as ordinary RAM, the value in the general-purpose register is unchanged by a reset,
meaning that the state before the reset is held. However, at power-on, the value is undefined.
Table 3.3-1 shows the typical functions of the general- purpose register.
Table 3.3-1 Typical Functions of the General-purpose Register
Register Name
R0 to R7
RW0 to RW7
RL0 to RL3
Used as operands for various instructions
Note:
R0 can also be used as the barrel shift counter or the normalized instruction counter.
Used as addressing
Used as operands for various instructions
Note:
RW0 can also be used as the string instruction counter.
Used as linear addressing
Used as operands for various instructions
Function
CHAPTER 3 CPU
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