Fujitsu manual F2MC-8FX Registers, F2MC-8FX General-Purpose Registers

CHAPTER 3 REGISTERS

3.1F2MC-8FX Registers

In the F2MC-8FX series, there are two types of registers: dedicated registers in the CPU, and general-purpose registers in memory.

■F2MC-8FX Dedicated Registers

The dedicated register exists in the CPU as a dedicated hardware resource whose application is restricted to the CPU architecture.

The dedicated register is composed of seven types of 16-bit registers. Some of these registers can be operated with only the lower 8 bits.

Figure 3.1-1shows the configuration of seven dedicated registers.

Figure 3.1-1 Configuration of Dedicated Registers

Initial value

FFFDH

0000H

0000H

0000H

0000H

0000H

16 bits

PC

A

T

IX

EP

SP

RP DP CCR

Program counter: indicates the location of the stored instructions

Accumulator: temporarily stores the result of operations and transfer

Temporary accumulator: performs operations with the accumulator

Index register: indicates address indexes

Extra pointer: indicates memory addresses

Stack pointer: indicates the current location of the top of the stack

Program status: stores register bank pointers, direct bank pointer and condition codes

CCR: IL1, 0 = 11

	Other flags = 0 PS
RP	: 00000
DP	: 000

■F2MC-8FX General-Purpose Registers

The general-purpose register is as follows:

•Register bank: 8-bit length: stores data

16