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Tell me why this don't bink a led on a 16f88 it works on all the rest.

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be80be

Well-Known Member
:confused:I can't see why this will not work I can't get a 16f88 to Bink a led on portB it will portA
Code:
LIST	p=16F88		;tell assembler what chip we are using
	include "P16F88.inc"		;include the defaults for the chip
	__CONFIG    _CONFIG1, _CP_OFF & _CCP1_RB0 & _DEBUG_OFF & _WRT_PROTECT_OFF & _CPD_OFF & _LVP_ON & _BODEN_OFF & _MCLR_ON & _PWRTE_ON & _WDT_OFF & _INTRC_IO
     __CONFIG    _CONFIG2, _IESO_OFF & _FCMEN_OFF
	cblock 	0x20 			;start of general purpose registers
	d1
	d2
	d3
	endc
	W_TEMP         EQU        0x7D  ; w register for context saving (ACCESS)
	STATUS_TEMP    EQU        0x7E  ; status used for context saving (ACCESS)
	PCLATH_TEMP    EQU        0x7F  ; variable used for context saving
    ORG     0x0000            ; processor reset vector
    GOTO    START             ; go to beginning of program
	
START:
	banksel	OSCCON
	movlw b'00111111'
	movwf	OSCCON	
RESET   clrf    STATUS          ;                                 |B0
    clrf    PORTA           ; clear Port A data latches       |B0
    clrf    PORTB           ; clear Port B data latches       |B0
    movlw   h'07'           ;                                 |B0
    movwf   CMCON           ; turn comparator off             |B0
    bsf     STATUS,RP0      ; select bank 1                   |B1
    clrf    TRISA           ; port A all outputs              |B1
    clrf    TRISB           ; port B all outputs              |B1
    bcf     STATUS,RP0      ; select bank 0                   |B0

	goto	main

main: 

	goto blinkleds
blinkleds:
	banksel	PORTB
    bsf 	PORTB,2
	call 	delay
	bcf		PORTB,2
	call 	delay	
	goto	blinkleds
delay		;999997 cycles
	movlw	0x08
	movwf	d1
	movlw	0x2F
	movwf	d2
	movlw	0x03
	movwf	d3
Delay_0
	decfsz	d1, f
	goto	$+2
	decfsz	d2, f
	goto	$+2
	decfsz	d3, f
	goto	Delay_0

			;3 cycles
	goto	$+1
	nop

	retlw 0x00

	end
 
I have mclr pulled up with a 10 k I remove that line the led comes on and stays on
Maybe I need a night light. LOL. It will bink it just takes about 2 min to do so.
 
Last edited:
The only thing I can see strange is that the clock is set to 500kHz and so your delay is 8 seconds instead of 1 second.

Edit, You also have the bottom two bits of OSCCON set which is reserved! Just write 0x72 to OSCCON.

Mike.
 
Last edited:
In the data sheet it said high speed
Code:
START:
	banksel	OSCCON
	movlw b'0111111'
	movwf	OSCCON
that not right.
 
That is loading OSCCON with 0x3f which gives a 500kHz clock and a reserved operating mode. To do 0x72 in binary would be b'01110010'.

Mike.
 
I see you can't do it the way I thought I thought that as long as
111 bits 6-4
1 bit 3 = 1
1 bit 2 = 1
11 bits 1-0
11111111 and last one don't count.
Thanks I get it. dumie me
 
Last edited:
The bits are arranged MSB first I.E. 76543210.

So, to set bits 6, 5 & 4 to 1 you would do '01110000'

You can leave of leading zeros and so b'1001' is the same as d'9'.

Mike.
 
I locked this chip up with the wrong config did two that way turned LVP off and a pickit 2 will not want to program it. With out setting the chip to Vdd
 
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PK2 should be able to blank a chip with LVP set. The only problem I know about is if you enable the timer1 oscillator as this uses the same pins as the ICSP. However, this can also be circumvented.

Mike.
 
Well I don't no what I did besides set LVP to off the code is the same but I turn LVP off. To get the chip to program. I had to set the programmer To use VPP frist program entry and set vdd on. Then It let me Blank the chip.
 
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