UPD75518 NEC, UPD75518 Datasheet - Page 18

• Manufacturer Part Number: UPD75518
• Description: 4 BIT SINGLE-CHIP MICROCOMPUTER
• Manufacturer: NEC

18
manipulation for 1-bit data, 4-bit data, and 8-bit data, so that very efficient and simple programming can be
performed.
0
F
As summarized in Table 2-1, the PD75518(A) allows both direct and indirect addressing in data memory
Examples 1. The 8-bit data of port 4 and port 5 are transferred to addresses 20H and 21H.
H
H
DECS HL
0H
Automatic
decrement
DECS L
DECS L
2. When P02 is 0, P33 is set.
3. A different value is output to port 6, depending on the status of P10.
CLR1
IN
MOV
SKT
SET1
SKF
MOV
MOV
SEL
OUT
4-bit transfer
MBE
XA, PORT4 ; XA
20H, XA
PORT0.2
PORT3.3
PORT1.0
A, #1010B
A, #0101B
MB15
PORT6, A
4-bit
manipulation
8-bit
manipulation
DECS D
DECS H
INCS D
INCS H
@HL
@DL
Fig. 2-2 Updating Static RAM Addresses
; MBE
; (21H, 20H)
; Skip if bit 2 of port 0 is 1
; Set bit 3 of port 3
; Skip if bit 0 of port 1 is 0
; A
; A
; or CLR1 MBE
; Port 6
INCS L
INCS L
Automatic
increment
1010B (string effect)
0101B (string effect)
INCS HL
Ports 5, 4
0
A
Direct
addressing
Bit manipulation
4-bit
8-bit
XA
DECS DE
DECS E
Bit manipulation
@H + mem.bit
4-bit transfer
DECS D
DECS H
INCS D
INCS H
@DE
INCS E
PD75518(A)
INCS DE
FH