Srp/Srp0/Srp1; Set Register Pointer - Samsung S3C80A5B User Manual

8-bit cmos
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INSTRUCTION SET

SRP/SRP0/SRP1

SRP
src
SRP0
src
SRP1
src
Operation:
If src (1) = 1 and src (0) = 0 then:
If src (1) = 0 and src (0) = 1 then:
If src (1) = 0 and src (0) = 0 then:
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:
opc
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.
6-80

— Set Register Pointer

src
RP0 (3–7)
?
src (3–7)
RP1 (3–7)
?
src (3–7)
RP0 (4–7)
?
src (4–7),
RP0 (3)
?
0
RP1 (4–7)
?
src (4–7),
RP1 (3)
?
1
Bytes
Cycles
2
Opcode
Addr Mode
(Hex)
4
31
S3C80A5B
src
IM

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