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Chapter 5 CPU Registers
1.General-purpose Registers
Chapter 5 CPU Registers

1. General-purpose Registers

Registers R0 through R15 are general-purpose registers. These registers are used for accumulator and
memory access pointers on various operations.
Figure 1-1 General-purpose Registers
Of 16 registers, the following registers are reserved for special application.
R13: Virtual accumulator
R14: Frame pointer
R15: Stack pointer
Initial values by reset are indeterminate for R0 through R14. Initial value by reset is 00000000H(SSP value)
for R15.

2. Dedicated Registers

Dedicated registers consist of program counter (PC), program status (PS), table-base register (TBR), return
pointer (RP), system stack pointer (SSP), user stack pointer (USP) and multiply & divide register (MDH/MDL).
Figure 2-1 Dedicated Registers List
XXXX XXXXH
XXXX XXXXH
...
...
...
...
0000 0000H
AC
FP
SP
R0
R1
R12
R13
R14
R15
...
...
...
...
32 bit

[Initial value]

Program counter
Program status
Table-base register
Return pointer
System stack pointer
User stack pointer
Multiply & divide register