I work on 5402 DSP. I face a problem in I/O. 5402 has HPIport which
can also be used as IO Port. I am using this port as Output.
The problem is Iam able to write to the IO in Main loop, but is ISR
the port is not in control. I written a toggling code, the pins
toggled well in mainloop, but the same didnt work in ISR.
I Tried both Asm and C, no use. in asm, i tried different
instructions to write to the pin, it worked only in main loop.
This applied for all 8 I/Os.
The interrupt i use is Timer 0
THis is the flow of my code.
----------------------
I/O Init:-
Config the GPIOCR direction
----------------------
Timer Init:-
Enable Global interrupts at INTM
Enable Timer 0 interupt at IMR
Stop the Timer - TCR
Load TIM with timer reload value
Start the timer
----------------------
ISR:-
Stop the Timer
Read the port
Compliment it
Write back
Load the TIM with timer reload
Start the timer
Return
----------------------
Anyone has an idea why is it so?
Note:I have grounded the HPIENA pin in DSP, to disable the HPI
Functionality[as per datasheet]
Thanks,
Vijay
