PORTx or LATx

Hi All,

I have tried looking for some documentation on this site and www.microchip.com which describes the differences of PORTx or LATx?

Can anyone help?
Mark

When LATx is read it returns the value that was last written to the port.
When PORTx is read it returns the value that is on the pins, even if the pin is set to output.

So, when setting or clearing an output pin use LATx. When testing an input pin use PORTx.

The difference is subtle but can cause problems.
For example,
If you have a capacitive load on bit 3 of a port and do the following sequence,
bsf PORTx,3
bcf PORTx,4
then the capacitive load on bit 3 may not have charged yet and when the processor reads the port during the bcf, it will read bit 3 as low and will subsequently write it back as 0. By using LATx this problem doesn't occur.

Mike.

Aha, Thanks

normally, use LATx.