Srp/srp0/srp1 – Samsung S3F80JB User Manual

Page 208

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INSTRUCTION SET

S3F80JB

6-80

SRP/SRP0/SRP1

Set Register Pointer

SRP

src

SRP0

src

SRP1

src

Operation:

If src (1) = 1 and src (0) = 0 then: RP0 (3–7)

← src

(3–7)

If src (1) = 0 and src (0) = 1 then: RP1 (3–7)

← src

(3–7)

If src (1) = 0 and src (0) = 0 then: RP0 (4–7)

← src

(4–7),

RP0

(3)

← 0

RP1

(4–7)

← src

(4–7),

RP1

(3)

← 1

The source data bits one and zero (LSB) determine whether to write one or both of the register
pointers, RP0 and RP1. Bits 3–7 of the selected register pointer are written unless both register
pointers are selected. RP0.3 is then cleared to logic zero and RP1.3 is set to logic one.

Flags:

No flags are affected.

Format:

Bytes Cycles Opcode

(Hex)

Addr Mode

src

opc src

2 4 31

IM

Examples:

The statement

SRP #40H

sets register pointer 0 (RP0) at location 0D6H to 40H and register pointer 1 (RP1) at location
0D7H to 48H.

The statement "SRP0 #50H" sets RP0 to 50H, and the statement "SRP1 #68H" sets RP1 to
68H.

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