Intel 87C196CA, Supplement To User’S Manual

Page: 39 / 136

4-5
STANDARD AND PTS INTERRUPTS
INT_PEND
Address:
Reset State:
0009H
00H
When hardware detects an interrupt request, it sets the corresponding bit in the interrupt pending
(INT_PEND or INT_PEND1) registers. When the vector is taken, the hardware clears the pending bit.
Software can generate an interrupt by setting the corresponding interrupt pending bit.
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
7:0
†
Any set bit indicates that the corresponding interrupt is pending. The interrupt bit is cleared
when processing transfers to the corresponding interrupt vector.
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 shared
interrupt. Write the EPA mask registersto 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 4-3. Interrupt Pending (INT_PEND) Register