Post by thread:[PIC]: '877 interrupts when disabled

Sorry for the double post all, I forgot the [PIC] on the post.... I'm not currently running a watchdog, I didn't want it to mask any problems that may occur (comments on this approach welcome), I've tried disabling the Brownout detect bit, and I doubt EMI(though I will include a little diagram of the switch buffering for all to look at. switch circuit: ---Vcc | [10k] | o---|-------|---[1K]---PORTB, 6 | | ===0.1uF V 5V transorb | --- | | o---|-------|---Gnd hope this comes out, notes on code: I have two LEDs on PORTC, 4 and 5 two switches buffered as above on PORTB, 6 and 7 muxes for more I/O on PORTS A and C this is stripped down code to try and isolate the problem, with a lot of stuff added to the ISR to clock registers out the LEDs (I use a DSO to catch the data) code: ; This is to test the serial output of the PIC list p=16f873 include "p16F873.inc" ; Constants ESC equ 0x1b ACK equ 0x06 CR equ 0x0d SW1EN equ 0x00 ; PORT C SW2EN equ 0x05 ; PORT A SW3EN equ 0x02 ; PORT C SW4EN equ 0x03 ; PORT C SW_SEL1 equ 0x01 ; PORT A SW_SEL2 equ 0x02 ; PORT A SW_SEL3 equ 0x03 ; PORT A SW_DATA equ 0x00 ; PORT A ;Variables ***************************************** delaycounter equ 0x20 delaycounter2 equ 0x21 delaycounter3 equ 0x22 delaycounter_ms equ 0x29 switch equ 0x25 setup_switch equ 0x26 dip_switch equ 0x27 denom equ 0x28 module_number_hi equ 0x30 module_number_lo equ 0x31 temp_w equ 0x23 temp_status equ 0x24 led_flasher equ 32 led_flasher2 equ 33 led_flasher3 equ 34 serial_buffer equ 0x40 ORG 0x000 clrf PCLATH goto start__code ORG 4 _interrupt movwf temp_w swapf STATUS, W clrf STATUS movwf temp_status movlw A'I' movlw B'00100000' movf INTCON, W movlw 0x50 bsf PORTC, 4 bsf PORTC, 5 ; call delayWms nop nop nop bcf PORTC, 4 nop nop nop bcf PORTC, 5 bsf PORTC, 4 btfsc PIE1, 0 bsf PORTC, 5 movlw 0x50 ; call delayWms nop nop nop bcf PORTC, 4 nop nop nop bcf PORTC, 5 bsf PORTC, 4 btfsc PIE1, 1 bsf PORTC, 5 movlw 0x50 ; call delayWms nop nop nop bcf PORTC, 4 nop nop nop bcf PORTC, 5 bsf PORTC, 4 btfsc PIE1, 2 bsf PORTC, 5 movlw 0x50 ; call delayWms nop nop nop bcf PORTC, 4 nop nop nop bcf PORTC, 5 bsf PORTC, 4 btfsc PIE1, 3 bsf PORTC, 5 movlw 0x50 ; call delayWms nop nop nop bcf PORTC, 4 nop nop nop bcf PORTC, 5 bsf PORTC, 4 btfsc PIE1, 4 bsf PORTC, 5 movlw 0x50 ; call delayWms nop nop nop bcf PORTC, 4 nop nop nop bcf PORTC, 5 bsf PORTC, 4 btfsc PIE1, 5 bsf PORTC, 5 movlw 0x50 ; call delayWms nop nop nop bcf PORTC, 4 nop nop nop bcf PORTC, 5 bsf PORTC, 4 btfsc PIE1, 6 bsf PORTC, 5 movlw 0x50 ; call delayWms nop nop nop bcf PORTC, 4 nop nop nop bcf PORTC, 5 bsf PORTC, 4 btfsc PIE1, 7 bsf PORTC, 5 movlw 0x50 ; call delayWms nop nop nop bcf PORTC, 4 nop nop nop bsf PORTC, 4 bsf PORTC, 5 movlw 0x50 ; call delayWms nop nop nop nop nop nop bcf PORTC, 5 ; btfsc STATUS, Z ; bsf PORTC, 5 ; xorwf PORTC, F ; clrf INTCON ; clrf PIR1 ; clrf PIE1 ; bsf PORTC, 5 ; movwf TXREG ; banksel TXSTA ;tx_wait3 ; btfss TXSTA, TRMT ; goto tx_wait3 ; movlw 0x30 ; movwf delaycounter ;tx_wait4 ; decfsz delaycounter, F ; goto tx_wait4 ; banksel TXREG ; bcf PORTC, 5 ; Disable CTS ; call tx_w ; movlw B'00010000' ; xorwf PORTC, 1 ; bsf PORTC, 4 ; btfsc PIR1, RCIF ; call rx_data ; clrf PIR1 bcf INTCON, T0IF ;clear interrupt flag swapf temp_status, W movwf STATUS swapf temp_w, F swapf temp_w, W retfie start__code _main__code initialisation banksel TRISC movlw B'00000001' ; init PORTA movwf TRISA movlw 0x06 movwf ADCON1 movlw 0xff ; init PORTB movwf TRISB movlw B'11000010' ; init PORTC movwf TRISC movlw 0x0a ; init Baud Rate 19200 movwf SPBRG bsf TXSTA, CSRC bsf TXSTA, TXEN bsf TXSTA, BRGH ; movlw B'00100000' ; Enable RX interupt ; movwf PIE1 ; bsf PIE1, RCIE clrf PIE1 banksel RCSTA bsf RCSTA, SPEN bsf RCSTA, CREN ; bsf PORTC, 5 // Enable CTS ; movlw B'11001000' ; movwf INTCON clrf INTCON clrf PORTC movf RCREG, W movf RCREG, W movlw B'00100000' movwf PORTA movlw B'00001101' movwf PORTC movlw serial_buffer movwf FSR label_0001 ; movlw B'00010000' ; xorwf PORTC, F ; movlw 0x30 ; call tx_w ; movlw 0xff ; call delayWms btfss PORTB, 6 goto debounce_read ; movlw 0x31 ; call tx_w goto label_0001 debounce_read clrf delaycounter clrf delaycounter2 debounce_wait_read decfsz delaycounter, F goto debounce_wait_read decfsz delaycounter2, F goto debounce_wait_read btfss PORTB, 6 goto read_mode goto label_0001 read_mode movlw B'00010000' xorwf PORTC, F ; movlw 0x30 ; call tx_w movlw 0xff call delayWms ; movlw 0x30 ; call tx_w goto label_0001 {Original Message removed}