AY0438 Datasheet, PDF (5/11 Pages) Microchip Technology – 32-Segment CMOS LCD Driver

AY0438
;The DP are not connected, but can be connected to seg8, 16, 24 & 32.
;For each digit, the segments are connected as:
;
Seg A --> seg(8*n + 1)
;
Seg B --> seg(8*n + 2)
;
Seg C --> seg(8*n + 3)
;
Seg D --> seg(8*n + 4)
;
Seg E --> seg(8*n + 5)
;
Seg F --> seg(8*n + 6)
;
Seg G --> seg(8*n + 7)
;where n = 0, 1, 2 and 3 for MSD, 3rdSD, 2ndSD and LSD respectively.
;The firmware uses the values in registers:
;
MSD, THRDSD, SCNDSD and LSD to determine the values to be
;pulsed to the AY0438.
;In this example, a pushbutton connected to PORTB bit 7
;is checked periodically to see if it has been pressed. If so,
;the LCD values in locations MSD to LSD are updated.
;*************************************************************************
list p=16c71,f=inhx8m
;
;
MSD
equ
0x20
THRDSD equ
0x21
SCNDSD equ
0x22
LSD
equ
0x23
count equ
0x24
temp equ
0x25
PORTB equ
0x06
#define CLK
PORTB,0
#define DATAIN PORTB,1
#define LOAD PORTB,2
#define UPDATELCD PORTB,7
w
equ
0
STATUS equ
0x03
C
equ
0
RP0
equ
5
OPTION equ
0x81
RBPU equ
7
PCL
equ
0x02
PCLATH equ
0x0A
;
;
org
0
goto start
org
0x10
;
;This DecodeValue table must reside in page 0 for this program to work
;
DecodeValue
addwf PCL
retlw B'00111111'
;decode for 0
retlw B'00000110'
;decode for 1
retlw B'01011011'
;decode for 2
retlw B'01001111'
;decode for 3
retlw B'01100110'
;decode for 4
retlw B'01101101'
;decode for 5
© 1995 Microchip Technology Inc.
DS70010I-page 5