> setint:
>         nop
>         BANK_1
>         movlw    b'11000000'  ;

Identifying bits would be helpful

;         1xxxxxxx   PORTB pullups disabled
;         x1xxxxxx   rising edge on RB0

>         movwf    OPTION_REG
>         BANK_0
>         movlw    b'11011000'  ;Enable the interrupts

;          bsf  gie
;          bsf  peie
;          bsf  inte
;          bsf  rbie

>         movwf    INTCON

Figure 12.9 of DS30292B (F877 manual) shows that PORTB
interrupts aren't part of the PEI system. Could that be causing
a problem in your set up ? I'm not familiar with MATLAB BTW

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