st2064b Sitronix Technology Corporation, st2064b Datasheet - Page 41

• Manufacturer Part Number: st2064b
• Description: 8 Bit Microcontroller With 64k Bytes Rom
• Manufacturer: Sitronix Technology Corporation

Ver. 3.0
Port_ISR
?Scan_PB
Interrupt-Subroutine
PHA
PHX
LDA
STA
STA
STZ
RMB3
LDX
RMB4
LDA
SMB4
SMB3
STX
JSR
ROL
LDA
BCS
.
.
PLX
PLA
RTI
:
:
:
:
wait 12us
#11111110B
<ScanValue
<PB
<PAK
<LSEL
#$FF
<LCTL
<PA
<LCTL
<LSEL
<PAK
Store-Key-Data
<Scanvalue
<Scanvalue
?Scan_PB
;
;;Initial scanning value for Port-B
;debounce are enabled together, keyboard awaking
;;This subroutine should be defined by user
;;Shift scanning value left
;; Port-A used as normal I/O
;;Change segments to be Port-B
;Wait for return line to be stable
;If keyboard awaking pulses and hardware
;pulses must be disabled before latch Port-A.
;;Change Port-B to be segments
;;Port-A used as keyboard return line
41/57
No
W a it P or t-A to b e Stab le
P or t-A set to r etu r n lin e
O u tp u t Sca n Valu e on
& Set to Nor m a l I/O
T u r n O F F P or t-B &
E n d of Sca n n in g?
T u r n O N P or t-B
Stor e K ey Data
R ead P or t-A
Scan L in es
R T I
Yes
ST2064B
5/8/09