Hello,
some time ago the compiler option --isr_save_vcu_regs was added to fix the VCU re-entrancy problem when using VCU (also hardware CRC) in different contexts.
This option results in adding a few instructions in the beginning and end of all interrupt routines that saves and restores VCU registers. In the case of VCRC it is 2x four instructions.
The side effect of this is that all interrupts now will have worse latency of additional 4 cycles. This is true also for interrupts that not use the VCU at all. The user can do nothing about it.
On the other hand there is an INTERRUPT pragma that can be used to shorten the ISR's latency when ISR nesting is not used (HPI and LPI options). This is accomplished by disabling the standard FPU registers full save & restore. This is great are we are using it a lot.
So our request is to add similar option to disable the VCU registers save/restore on the selected interrupts on the responsibility of the user. This applies only to situations when --isr_save_vcu_regs option is used.
What do you think about such feature?
Best regards,
Andy
