Ti c66x DSP system events and Its Application-5.10 (three scenarios for creating ISR)

ISFP is a command package for service interruption. There are three scenarios for creating ISR:

1. Eight commands in An ISFP package can satisfy ISR requirements.

2. ISR can occupy multiple consecutive ISFP (provided that the following interruptions are not used)

3. ISR is located outside of ist

In the preceding figure, B IRP indicates the interruption from the shielded (int4 ~ 15. Because instruction B has five cycle delays, five NOP commands are added after Instruction B jumps to prevent the CPU from executing other programs. For example, in the first figure, if the command after B IRP is a single cycle command (such as NOP 1), the CPU will finish executing the first four commands of int6 ISFP, this is not allowed becauseExecute the first four commands of int6The consequences are unpredictable.

Therefore, add NOP 5 or 5 single cycle commands to the B IRP command.