PIC 16F874A
arssa2020
i am not sure i am in the right newsgroup, i tried to post on
comp.arch.embedded.picbasic, but google would say its not archived no
more.
back to the dilema, i am using PIC16F874A in a design to monitor
battery for a handheld.
still new to the PIC and the PIC basic, i try to initialize the I/O
ports (A through E) and set the corresponding bits to Input/output.
i am writing some values to PORTA, using the Debbuger and the watch
window, i monitor the values of PORTA, however, when i write a certain
value to it, the watchlist will show another value.
for e.g, here is what i do first
<code>
bsf STATUS,RP0 ; select register bank 1
movlw b'10011111'
movwf TRISB ; set port B
bcf OPTION_REG,NOT_RBPU ; turn on pull ups
movlw b'00000011' ;
movwf TRISA ; set the OUTPUT port (PORTA)
movlw b'10000000' ; set Pic_txD as input, all others as
outputs
movwf TRISC ; set the CONTROL port (PORTC)
movlw b'00000000' ; set port D as all outputs
movwf TRISD ; set the KEYSTRB port (PORTD)
movlw b'00000111' ; set port E (not being used)
movwf TRISE ; set port E
</code>
i watch TRISA,B,... etc and all of them appear to have the right value
in the watchlist.
then, i try to init the ports to a certain values, like
<code>
; Intialize ports
bcf STATUS,RP0 ;select bank0
movlw b'00011101' ;0x1D
movwf PORTA
</code>
in the watchlist, PORTA seem to have a value of "0x0C" not "0x1D"
now why is that? what i am doin wrong?
ur help is appreciated
regards
Neil Cherry
You might want to take this over to the PIC list:
http://mailman.mit.edu/mailman/listinfo/piclist
Pay careful attention to the Topic prefix (your's would be:
[PIC]: PIC 16F874A
though you might want a better description of the problem).
--
Linux Home Automation Neil Cherry nch...@comcast.net
http://home.comcast.net/~ncherry/ (Text only)
http://hcs.sourceforge.net/ (HCS II)
http://linuxha.blogspot.com/ My HA Blog