4-3
STANDARD AND PTS INTERRUPTS
4.2.1 Interrupt Mask RegistersFigures 4-1 and 4-2 illustrate the interrupt mask registers for the 8XC196Lx microcontrollers.
INT_MASK Address:
Reset State: 0008H
00H
The interrupt mask (INT_MASK) register enables or disables (masks) individual interrupt requests.
(The EI and DI instructions enable and disable servicing of all maskable interrupts.) INT_MASK is the
low byte of the processor status word (PSW). PUSHF or PUSHA saves the contents of this register
onto the stack and then clears this register. Interrupt calls cannot occur immediately following a push
instruction. POPF or POPA restores it.
7 0
LA AD EPA0 EPA1 EPA2 EPA3 EPA
x
7 0
LB J1850RX J1850TX AD EPA0 EPA1 EPA2 EPA3 EPA
x
7 0
LD — EPA0 EPA1 EPA2 EPA3 EPA
x
Bit
Number Function
7:0Setting a bit enables the corresponding interrupt.
Bit Mnemonic Interrupt Description
J1850RX J1850 Receive (LB only)
J1850TX J1850 Transmit (LB only)
AD A/D Conversion Complete (LA, LB)
EPA0 EPA Capture/Compare Channel 0
EPA1 EPA Capture/Compare Channel 1
EPA2 EPA Capture/Compare Channel 2
EPA3 EPA Capture/Compare Channel 3
EPA
x
†† Shared EPA interrupt
†† EPA 6–9 capture/compare channel events, EPA 0–1 compare channel events†††, EPA
0–3 and 8–9 capture/compare overruns, and timer overflows can generate this
multiplexed interrupt. The EPA mask and pending registers decode the EPA
x
interrupt.
Write the EPA mask registers to enable the interrupt sources; read the EPA pending
registers to determine which source caused the interrupt.
††† 87C196LA, LB only.
Bits 6–7 are reserved on the 87C196LA, and bits 5–7 are reserved on the 83C196LD. For
compatibility with future devices, write zeros to these bits.

Figure 4-1. Interrupt Mask (INT_MASK) Register