Hi everyone!
Im very new to PIC programming and hope to get some help with timer1... I'm using MPLAB IDE 8.20
I am required to create a 75mS delay with timer1.
I am using a PIC 16F870 with a 4Mhz crystal
So the instruction cycle is 1 microsecond.
Sorry Im really totally new to this and just havent got my head around programming yet. I havent found much help on timer1 on the net either.
I have used the following formula to get the number i have to put into TMR1 to achieve a 75mS delay:
65536 - (75mS x (1Mhz / 8)
which gives me 56161 which is DB61 in hex
So I then load DB into TMR1H and 61 into TMR1L. Is this right so far?
And this is what Ive written so far:
BCF PIR1,0
CLRF TMR1L
MOVLW 0X0B
MOVWF TMR1H
MOVLW 0XDC
MOVWF TMR1L
TIME1
BSF T1CON,0
BTFSS PIR1,0
GOTO TIME1
EDIT:
For some reason this code is only giving me a 62mS delay in the stopwatch
To be honest Im a bit stuck right now as to how to continue from here... hope someone can point me in the right direction.![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
cheers!
Im very new to PIC programming and hope to get some help with timer1... I'm using MPLAB IDE 8.20
I am required to create a 75mS delay with timer1.
I am using a PIC 16F870 with a 4Mhz crystal
So the instruction cycle is 1 microsecond.
Sorry Im really totally new to this and just havent got my head around programming yet. I havent found much help on timer1 on the net either.
I have used the following formula to get the number i have to put into TMR1 to achieve a 75mS delay:
65536 - (75mS x (1Mhz / 8)
which gives me 56161 which is DB61 in hex
So I then load DB into TMR1H and 61 into TMR1L. Is this right so far?
And this is what Ive written so far:
BCF PIR1,0
CLRF TMR1L
MOVLW 0X0B
MOVWF TMR1H
MOVLW 0XDC
MOVWF TMR1L
TIME1
BSF T1CON,0
BTFSS PIR1,0
GOTO TIME1
EDIT:
For some reason this code is only giving me a 62mS delay in the stopwatch
To be honest Im a bit stuck right now as to how to continue from here... hope someone can point me in the right direction.
cheers!
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