st2032a Sitronix Technology Corporation, st2032a Datasheet - Page 38

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

Interrupt-Subroutine
Port_ISR
?Scan_PB
Ver 2.4
PHA
PHX
LDX
LDA
STA
STA
STZ
nop
nop
nop
LDA
STX
JSR
SEC
ROL
LDA
BCS
.
.
PLX
PLA
RTI
#00010111B
#11111110B
<ScanValue
<PB
<LSEL
<PA
<LSEL
Store-Key-Data
<Scanvalue
<ScanValue
?Scan_PB
;;X: Value for LSEL when activate segments
;;Shift working zero to left
;;Set Working zero for Port-B
;;Disable segment waveforms
;;Wait for return line to be stable
;;Enable segment waveforms
;;Keep on scanning until ScanValue = FF
38/54
FIGURE 14-6 Port Interrupt Flow Chart
No
Wait Port-A to be Stable
Output Scan Value on
Turn OFF Port-B
End of Scanning?
Turn ON Port-B
Store Key Data
Read Port-A
Scan Lines
RTI
Yes
ST2032A
9/13/07