Updating Static Ram Addresses - NEC PD750004 User Manual

µPD750008 USER'S MANUAL
Example 2. The data memory of 00H to FFH is cleared to 0.
x 0H
0 x H
DECS L
Automatic
decrement
DECS L
DECS HL
F x H
2 8
CLR1 RBE
CLR1 MBE
MOV XA,#00H
MOV HL,#04H
LOOP: MOV @HL,A
INCS HL
BR LOOP
Figure 3-3. Updating Static RAM Addresses
DECS D
@DL
4-bit transfer
INCS D
DECS H
@HL
4-bit
manipulation
8-bit
manipulation
INCS H
; (HL) <– A
; HL <– HL + 1
DECS E
INCS L
DECS DE
Direct
addressing
Bit manipulation
4-bit transfer
8-bit transfer
Automatic
increment
INCS L
INCS HL
DECS D
INCS E
@DE
4-bit transfer
INCS DE
INCS D
DECS H
@H + mem.bit
Bit manipulation
INCS H
x FH