MC68HC901P MOTOROLA [Motorola, Inc], MC68HC901P Datasheet - Page 33

• Manufacturer Part Number: MC68HC901P
• Description: Multi-Function Peripheral
• Manufacturer: MOTOROLA [Motorola, Inc]

Interrupt Structure
4.3.4 Interrupt In-Service Registers (ISRA, ISRB)
These registers indicate whether interrupt processing is in progress for a certain channel. A
bit is set whenever an interrupt vector number is passed for a interrupt channel during an
IACK cycle and the S bit of the vector register is a one. The bit is cleared whenever interrupt
service is complete for an associated interrupt channel, the S bit of the vector register is
cleared, or the processor writes a zero to the bit.
GPIP7-GPIP6 — General Purpose Interrupt Servicing
Timer A — Timer A Interrupt Servicing
Receiver Buffer Full — Receiver Buffer Full Interrupt Servicing
Receiver Error — Receiver Buffer Full Interrupt Servicing
Transmitter Buffer Empty — Transmitter Buffer Interrupt Servicing
Transmitter Error — Transmitter Error Interrupt Servicing
Timer B — Timer B Interrupt Servicing
4-10
ISRA REGISTER
RESET
FIELD
ADDR
BIT
1 = In-service.
0 = No service in progress.
1 = In-service.
0 = No service in progress.
1 = In-service.
0 = No service in progress.
1 = In-service.
0 = No service in progress.
1 = In-service.
0 = No service in progress.
1 = In-service.
0 = No service in progress.
1 = In-service.
0 = No service in progress.
GPIP7
7
0
GPIP6
6
0
TIMER A
MC68HC901 USER’S MANUAL
5
0
BUFFER
FULL
RCV
4
0
$0F
ERROR
RCV
3
0
BUFFER
EMPTY
XMIT
2
0
ERROR
XMIT
1
0
MOTOROLA
TIMER B
0
0