st2032a Sitronix Technology Corporation, st2032a Datasheet - Page 37

• Manufacturer Part Number: st2032a
• Description: 8 Bit Microcontroller With 32k Bytes Rom
• Manufacturer: Sitronix Technology Corporation

15.3 Keyboard-scan Function on LCD drives
LCD keyboard awaking pulses are combined with LCD
waveform. The purpose is to trigger Port-A interrupt to wake
up the system.
15.3.2 Keyboard-scan Function Example:
INITIAL_Port_And_LCD
Ver 2.4
VP
VP
V1
V2
V3
V4
V5
V1
V2
V3
V4
V5
SMB4
LDA
STA
a.
b.
c.
.
.
STZ
LDA
STA
STA
LDA
STA
LDA
STA
LDA
STZ
.
.
CLI
.
.
Keyboard : 64Keys (8x8)
Return Lines : Port-A
Scan Lines : Port-B
.
<LCTL
#000
<LSEL
<PCA
#FFH
<PA
<PCB
#10000000B
<PMCR
#00010000B
<IENA
<PA
<IREQ
11111B
FIGURE 15-3 LCD Segment Waveform (With Keyboard Awaking Pulses)
FIGURE 15-4 LCD Common Waveform (With Keyboard Awaking Pulses)
;;Enable Keyboard Awaking Waveform
;;Port-B/C Shared With SEGs
;;Set Port-A as Inputs for Return Line
;;Port-A Pull-High
;;Set Port-B as Outputs for Scan Line
;;Enable Pull up,Disable Debounce
;;Enable Port-A Interrupt
;;Reset Interrupt Request Register
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Note:
1. keyboard awaking pulses can only be turned
2. If there is crosstalk on the first line, please
on below 3V operating voltage.
turn on keyboard-scan function for better
quality.
FIGURE 14-5 Initial Flow Chart
Initial Interrupt/LCD
(Disable Debouncd)
Initial I/O
CLI
.
.
.
ST2032A
9/13/07