Jan-Erik,
     The compiler doesn't like NOP; Any suggestions?
Thanks,
rich!

On 10/20/2015 8:50 AM, Jan-Erik S=F6derholm wrote:
> Or simply (as a test) add 3-4 NOPs between each bit operation.
> That is easier and doesn't need any new variables or program logic.
>
> It will certainly remove all RMW issues apart from the very worst,
> that you should not see with a LCD module anyway...
>
> Jan-Erik.
>
>
>
> -----Ursprungligt meddelande-----
> Fr=E5n: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] F=F6r Is=
aac
> Marino Bavaresco
> Skickat: den 20 oktober 2015 15:37
> Till: Microcontroller discussion list - Public. <piclist@mit.edu>
> =C4mne: Re: [PIC]: Trying to get a 16F877A to talk to an LCD!
>
> Richard,
>
>
> Did you try to avoid RMW issues by using a shadow for the I/O ports?
> It is  possible to have RMW issues if then pin loading capacitance is too
> high or with other mysterious conditions.
>
> Instead of BCFing or BSFing the pins, do that in a file register and then
> copy its value to the port.
>
> eg.:
>
> unsigned char    ShadowPortA    =3D 0x04;    // EN starts disabled (1)
> ...
> PORTA    =3D ShadowPortA;
> TRISA    =3D 0x00;
> ...
> ShadowPortA    &=3D ~0x04; // Set EN =3D 0
> PORTA    =3D ShadowPortA;
> ...
>
> ShadowPortA    |=3D 0x04; // Set EN =3D 1
> PORTA    =3D ShadowPortA;
>
>
> Do not forget that both CMCON and ADCON1 must be set to 0x07.
>
>
> Cheers,
>
> Isaac
>
--=20
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