Rabbit 3000, User Manual

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90 Rabbit 3000 Microprocessor
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.
7.9.1 External Interrupts
There are two external interrupts. Each interrupt has 2 input pins that can be used to trig-
ger the interrupt. The inputs have a pulse catcher that can detect rising, falling or either ris-
ing or falling edges.
Table 7-9. Interrupts—Priority and Action to Clear Requests
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 QDSR.
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