HDSP-2301 HP [Agilent(Hewlett-Packard)], HDSP-2301 Datasheet - Page 22

• Manufacturer Part Number: HDSP-2301
• Description: Four Character 5.0 mm (0.20 inch) 5 x 7 Alphanumeric Displays
• Manufacturer: HP [Agilent(Hewlett-Packard)]

Figure 8. 8080A Microprocessor Program that Decodes a 32 Character
ASCII String Prior to Loading into the REFRESH CONTROLLER
0004
0005
E500
E000
E002
E003
E005
E007
E400
E401
E402
E403
E404
E407
E408
E40B
E40E
E40F
E410
E412
E414
E416
E417
E418
E419
E41A
E41C
E41D
E41E
E421
E422
E425
E427
E429
E42C
E42D
E430
E431
E434
E435
E438
E43B
E43D
E440
E443
E446
E449
E44A
E44D
E44E
E44F
E450
E451
LOC
07
FE
FF
00
00
F5
C5
D5
E5
2A
EB
2A
01
09
43
0E
3E
D3
78
86
5F
1A
D3
2B
0D
C2
EB
3A
D3
FE
CA
07
32
68
01
09
22
C3
3E
32
21
22
2A
2B
22
E1
D1
C1
F1
C9
OBJECT
CODE
E0
FF
E5
05
00
1F
20
FF
05
04
16
02
05
EF
3B
02
80
05
4D
FE
02
00
05
03
03
E0
E0
00
E4
E0
E4
E0
00
E0
E4
E0
E5
E0
E0
E0
SOURCE STATEMENTS
RDVR
CDVR
DECDR
ASCII
COLMN
COUNT
BASE
DATA
ORG
RFRSH
LOOP
FIRST
END
EQU
EQU
EQU
ORG
DW
DB
DW
DW
DS
PUSH
PUSH
PUSH
PUSH
LHLD
XCHG
LHLD
LXI
DAD
MOV
MVI
MVI
OUT
MOV
ADD
MOV
LDAX
OUT
DCX
DCR
JNZ
XCHG
LDA
OUT
CPI
JZ
RLC
STA
MOV
LXI
DAD
SHLD
JMP
MVI
STA
LXI
SHLD
LHLD
DCX
SHLD
POP
POP
POP
POP
RET
0004H
0005H
0E500H
0E000H
DATA
0FEH
0FFFFH
DECDR
32
0E400H
PSW
B
D
H
BASE
ASCII
B, 31
B
B, E
C, 32
A, 0FFH
CDVR
A, B
M
E, A
D
RDVR
H
C
LOOP
COLMN
CDVR
0EFH
FIRST
COLMN
L, B
B, 0080H
B
BASE
END
A, 0FEH
COLMN
H, DECDR
BASE
COUNT
H
COUNT
H
D
B
PSW
COLUMN
UPDATE COLMN FOR NEXT
REFRESH CYCLE
BASE
UPDATE BASE WITH ADDRESS OF
NEXT COLUMN IN DECODER ROM
DE
LOAD DE WITH ADDRESS NEXT COLUMN TO BE
DECODED IN DECODER ROM
HL
LOAD HL WITH ADDRESS OF RIGHTMOST ASCII SYMBOL
HL
UPDATE HL WITH ADDRESS OF NEXT SYMBOL TO LEFT
A
READ BYTE OF DECODED DATA FROM DECODER
RDVR
STORE BYTE OF DECODED DATA IN 74165
CDVR
TURN ON APPROPRIATE COLUMN DRIVER
STORE MACHINE STATUS ON STACK
BASE + 80
ASCII + 31
BASE
HL – 1
(DE + A)
2 COLMN + 1
NO
A
COLMN
CDVR
TURN OFF COLUMN DRIVERS
A
READ ASCII SYMBOL INTO A
H
(HL)
FF
REFRESHED
YES
COLUMN 5?
C
H
RFRSH
C
C = 0?
JUST
C – 1
14
32
(END)
COLMN
UPDATE COLMN TO TURN
ON COLUMN 1
BASE
UPDATE BASE WITH ADDRESS OF
COLUMN 1 DATA IN DECODER ROM
RESTORE MACHINE STATUS ON
STACK
(FIRST)
(LOOP)
COUNT
OPTIONAL 2 ms COUNTER
YES
NO
DECDR
FE
H
RETURN
COUNT –1