MB89130 View Datasheet(PDF) - Fujitsu

Part Name

Description

Manufacturer

MB89130

8-bit Proprietary Microcontroller

Fujitsu 

MB89130/130A 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 registers are provided :

Program counter (PC) :

A 16-bit register for indicating the instruction storage positions.

Accumulator (A) :

A 16-bit temporary register for storing arithmetic operations, etc. When the

instruction is an 8-bit data processing instruction, the lower byte is used.

Temporary accumulator (T) : A 16-bit 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 register for index modification

Extra pointer (EP) :

A 16-bit pointer for indicating a memory address

Stack pointer (SP) :

A 16-bit pointer for indicating a stack area

Program status (PS) :

A 16-bit register for storing a register pointer, a condition code

16 bits

PC

A

T

IX

EP

SP

PS

: Program counter

Initial value

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

23

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