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Rabbit 3000 Microprocessor User’s Manual
There is a priority among interrupts if multiple requests are pending, as shown in
Table 6-3.Interrupts marked as “cleared automatically” have their requests cleared when the inter-
rupt is first handled.
In the case of the external interrupts the only action that will clear the interrupt request is
for the interrupt to take place, which automatically clears the request. A special action
must be taken in the interrupt service routine for the other interrupts.
Table 6-3. Interrupt Priorities
Priority
Interrupt Source
Action Required to Clear the Interrupt
Highest
External 1
Automatically cleared by the interrupt acknowledge.
External 0
Automatically cleared by the interrupt acknowledge.
Periodic (2 kHz)
Read the status from the GCSR.
Quadrature Decoder
Read the status from the QDCSR.
Timer B
Read the status from the TBSR.
Timer A
Read the status from the TASR.
Input Capture
Read the status from the ICCSR.
Slave Port
Rd: Read the data from the SPD0R, SPD1R or SPD2R.
Wr: Write data to the SPD0R, SPD1R, SPD2R or write a dummy
byte to the SPSR.
Serial Port E
Rx: Read the data from the SEDR or SEAR.
Tx: Write data to the SEDR, SEAR, SELR or write a dummy byte
to the SESR.
Serial Port F
Rx: Read the data from the SFDR or SFAR.
Tx: Write data to the SFDR, SFAR, SFLR or write a dummy byte
to the SFSR.
Serial Port A
Rx: Read the data from the SADR or SAAR.
Tx: Write data to the SADR, SAAR, SALR or write a dummy byte
to the SASR.
Serial Port B
Rx: Read the data from the SBDR or SBAR.
Tx: Write data to the SBDR, SBAR, SBLR or write a dummy byte
to the SBSR.
Serial Port C
Rx: Read the data from the SCDR or SCAR.
Tx: Write data to the SCDR, SCAR, SCLR or write a dummy byte
to the SCSR.
Lowest
Serial Port D
Rx: Read the data from the SDDR or SDAR
Tx: Write date to the SDDR, SDAR, SDLR or write a dummy byte
to the SDSR