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144
μ
PD75517(A)
8. INSTRUCTION SET
8.1
μ
PD75517(A) INSTRUCTIONS
(1) GETI instruction
The GETI instruction references a two-byte table in the program memory and performs the following
three types of operations. This 1-byte instruction is very useful in reducing the number of program steps.
(a) A subroutine call is made to all the spaces, regarding data in a table as the call address of a call
instruction.
(b) A branch is made to all the spaces, regarding data in a table as the branch address of a branch
instruction.
(c) Data in a table is executed as a double-byte or 1-byte instruction.
The tables to be referenced by a GETI instruction are located at addresses 0020H to 007FH in the program
memory. That is, data can be set in up to 48 tables.
When describing a table address as an operand, describe an even address.
Cautions 1. A two-byte instruction which can be referenced by a GETI instruction must be a two-
machine-cycle instruction. (Except for the BRCB and CALLF instructions)
2. When referencing two 1-byte instructions with a GETI instruction, only the combinations
listed in the table below are valid.
3. Branch and subroutine instructions can be referenced by the GETI instruction only when
their destination addresses are in the 16K-byte space (0000H to 3FFFH). A branch or
subroutine instruction to an address from 4000H to 5F7FH cannot be referenced by the GETI
instruction.
Instruction of second byte
Instruction of first byte
MOV A,@HL
MOV @HL,A
XCH A,@HL
MOV A,@DE
XCH A,@DE
MOV A,@DL
XCH A,@DL
INCS
DECS
INCS
DECS
INCS
L
L
H
H
HL
INCS
DECS
INCS
DECS
INCS
E
E
D
D
DE
INCS
DECS
INCS
DECS
L
L
D
D