port output/input timing problem?

[websmith]

I had some broken code (keypad scan routine) over the weekend that I realy strugled with and after several (probably 50) attempts and changes got it to work but then lost track of what I fixed!

I'm writing out on half of port C and listening on the other half for a key press.
Is there any timing danger in doing this:
#use standard_io(c)...etc

output_c(0b11110111);
dummy = input_c();

compared to this approach:
set_tris_c(0b11110000);

PORTC = 0b11110111;
dummy = PORTC;

[asmallri]

This will not work, you really need to be using fast_IO. If you are using an 18F series PIC then you should write to the latch (LATC) and read from the port.
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Regards, Andrew

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