st2024c Sitronix Technology Corporation, st2024c Datasheet - Page 17

• Manufacturer Part Number: st2024c
• Description: 24k 8-bit Single Chip Microcontroller
• Manufacturer: Sitronix Technology Corporation

10.2.5 PA0/INTX
PA0
Falling or Rising edge is controlled by INTEG(PMCR[5]) and
the external interrupt is set up with “0” for falling edge and “1”
for rising edge. Please refer to the Figure 9-3.
Operating INTX interrupt step by step :
Ver 2.2
1.
2.
3.
4.
5.
can be used as an external interrupt input(INTX).
Set PA0 pin into input mode. (PCA[0])
Select edge level. (INTEG)
Clear INTX interrupt request flag. (IRX)
Set INTX interrupt enable bits. (IEX)
Clear CPU interrupt mask flag (I).
PA 0/INTX
PMCR[5]
FIGURE 10-3: INTX Logic Diagram
17/54
When programmer enables INTX and PT interrupts, PA0
trigger will occur. Both INTX and PT interrupts will happen
sequentially. Pelase refer to the operating steps.
Example :
Falling Edge Interrupt
RMB0
SMB5
RMB0
SMB0
CLI
.
.
.
.
.
.
<PCA
<PMCR
<IREQ
<IENA
;Set input mode.
;Rising edge.
;Clear IRQ flag.
;Enable INTX interrupt.
ST2024C
1/31/08