39
µ
PD17062
Example 2.
5.3.2 Notes on Using Unmounted Data Memory
As shown in Fig. 5-6, nothing is actually assigned to bit 0 (LSB) of address 72H of BANK1 of the port registers.
If a data memory manipulation instruction is executed for this address, the following operations are
performed:
(1) Device behavior
If a read instruction is executed, a 0 is read.
Executing a write instruction results in no change.
(2) Assembler behavior
Normal assembly is performed.
No error occurs.
(3) Emulator (IE-17K) behavior
If a read instruction is executed, a 0 is read.
Executing a write instruction results in no change.
No error occurs.
M1
M2
M3
MEM
MEM
MEM
0.15H
1.15H
2.15H
;
;
;
Bank Row address Column address
BANK1
MOV M1,
MOV M2,
MOV M3,
#0000B
#0000B
#0000B
;
;
;
; Assembler built-in macro instruction BANK ← 1
M1, M2, and M3 are defined symbolically in for different
banks, but are for BANK1 in this program. Thus, all of these
three instructions write 0s to data memory address 15H in BANK1.
Symbol definition pseudo instruction