8XC196L
X

SUPPLEMENT

7-6
7.1.3 EPA Interrupt Priority Vector RegisterFigure 7-7 illustrates the EPA interrupt priority vector (EPAIPV) register for the 8XC196Lx mi-crocontroller family.
EPAIPV Address:
Reset State: 1FA8H
00H
When an EPA
x
interrupt occurs, the EPA interrupt priority vector (EPAIPV) register contains a number
that identifies the highest priority, active, multiplexed interrupt source (see Table 7-2).
EPAIPV allows software to branch via the TIJMP instruction to the correct interrupt service routine
when EPA
x
is activated. Reading EPAIPV clears the EPA pending bit for the interrupt associated with
the value in EPAIPV. When all the EPA pending bits are cleared, the EPA
x
pending bit is also cleared.
7 0
— — — PV4 PV3 PV2 PV1 PV0
Bit
Number Bit
Mnemonic Function
5:7 Reserved; for compatibility with future devices, write zeros to these bits.
4:0 PV4:0 Priority Vector
These bits contain a number from 01H to 14H corresponding to the
highest-priority active interrupt source. This value, when used with the
TIJMP instruction, allows software to branch to the correct interrupt
service routine.

Figure 7-7. EPA Interrupt Priority Vector Register (EPAIPV)

Table 7-2. EPA Interrupt Priority Vectors

Value Interrupt Value Interrupt Value Interrupt

14H 0DH OVR1 06H OVR8
13H 0CH OVR2 05H OVR9
12H EPA6 0BH OVR3 04H COMP0
11H EPA7 0AH 03H COMP1
10H EPA8 09H 02H OVRTM1
0FH EPA9 08H 01H OVRTM2
0EH OVR0 07H 00H None
87C196LA, LB only; reserved on 83C196LD.