NEC PD750008 - Manual (Page 291)

271
CHAPTER 11 INSTRUCTION SET
For example, if MOVT XA,@PCDE is located at a as shown above, the table data in page 3 specified by
the contents of the DE register pair is transferred to the XA register pair instead of that in page 2.
Example The 16-byte data at addresses xxF0H-xxFFH in program memory is transferred to addresses
30H-4FH in data memory.
SUB: SEL MB0
MOV HL,#30H ; HL <– 30H
MOV DE,#0F0H ; DE <– F0H
LOOP: MOVT XA,@PCDE ; XA <– table data
MOV @HL, XA ; (HL) <– XA
INCS HL ; HL <– HL + 2
INCS HL
INCS E ; E <– E + 1
BR LOOP
RET
ORG xxF0H
DB xxH, xxH, ....... ; Table data
MOVT XA, @PCXA
Function: For the µPD750006 and µPD750008
XA <– ROM (PC
12-8
+XA)
Transfers the low-order four bits of the table data in program memory to the A register, and the high-order
four bits to the X register. The table data is addressed by the program counter (PC) with its low-order eight
bits (PC
7-0
) exchanged with the contents of the XA register pair.
The table address is determined by the contents of the program counter present when this instruction is
executed.
The table area must have necessary data loaded by an assembler pseudo instruction (DB instruction).
The program counter is not affected by the execution of this instruction.
Caution As with MOVT XA,@PCDE, when the instruction is located at address xxFFH, table data
in the next page is transferred.
Remark "Function" in this section is applicable to the µPD750006 and µPD750008 whose program
counters consist of 13 bits each. This is also applicable to the µPD750004 whose program
counter consists of 12 bits and the µPD75P0016 whose program counter consists of 14 bits,
however.