Rabbit Rabbit 4000, User Manual

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66 Rabbit 4000 Microprocessor User’s Manual
6.2 Operation
To ensure proper operation, all interrupt handler routines should be written according to
the following guidelines.
•
Push all registers to be used by the routine onto the stack before use, and pop them off
the stack before returning from the ISR.
•
Keep the ISR as short and fast as possible.
•
If the ISR will run for some time, lower the interrupt priority as soon as possible within
the ISR to allow other interrupts to occur.
•
A number of special rules apply to interrupts when operating in the system/user mode;
please see the appropriate chapter for more details.
6.3 Interrupt Tables
Table 6-1 shows the structure of the internal interrupt vector table. The first column is the
vector address offset within the table. The second column shows the vectors in the first
256 bytes of the table, and the third column shows the vectors in the second 256 bytes.
Table 6-1. Internal Interrupt Vector Table Structure
Offset
0x00 Periodic Interrupt —
0x10 Secondary Watchdog —
0x20 RST 10 —
0x30 RST 18 —
0x40 RST20 —
0x50 RST 28 —
0x60 Syscall instruction —
0x70 RST 38 PWM
0x80 Slave Port Sys/User Mode Violation
0x90 Write Protect Violation Quadrature Decoder
0xA0 Timer A Input Capture
0xB0 Timer B Stack Limit Violation
0xC0 Serial Port A Serial Port E
0xD0 Serial Port B Serial Port F
0xE0 Serial Port C Network Port A
0xF0 Serial Port D Timer C