How to set port to high impedance? TRIS seems not to be working.

[mpgmike]

In your example code you clear all TRIS bits making them all outputs. Try:

TRISA = 111111
TRISB = 111111
TRISC = 111111

frak:
TRISA.6 = 0
TRISC.3 = 0
HIGH PORTA.6
LOW PORTC.3
PAUSE 2
LOW PORTA.6
HIGH PORTC.3
PAUSE 2
TRISA.6 = 1
TRISC.3 = 1

TRISC.1 = 0
TRISC.2 = 0
HIGH PORTC.1
LOW PORTC.2
PAUSE 2
LOW PORTC.1
HIGH PORTC.2
PAUSE 2
TRISC = 0
GOTO frak

[CuriousOne]

As I understand, that RMW issue might happen due to current flowing in reverse direction thru the one of the led segments.
For the latch part, I'll try one, too bad there is no search option to tell, which part has latch and which does not.

[mpgmike]

Newer PICs have LATx registers that eliminate the RMW issues.

[richard]

charlieplexed correctly latx regs are not required at all