Electronic – How to tristate output digital pin on a pic 16 series microcontroller

coutputpictri-statexc8

I know that I can set digital output pins as high and low like this in c:

OUTPUT_PIN = 1;
OUTPUT_PIN = 0;

Is there any way to set that said pin as tristate or high impedance output, as some external chips (I'll be using sram chip) require tristated/high impedance inputs to them?

I'm using xc8 c compiler.

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Page 29 of the Microchip 41213D.pdf document has figure 6-1: enter image description here

The D FF labelled (TRIS LATCH) means that is the TRS-state latch. It controls (Gates) the signals from the data latch to turn off the P AND N transistors. The input to the TRSI Latch is the W Reg.

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Electronic – PIC32 Peripheral Pin Select for Digital Output

I suspect it's your config bits, the one thing you didn't post.

RA2/3 are the main oscillator pins.
RB4/RA4 are the secondary oscillator pins.
RB5/7/8/9 are JTAG.

All of those pins are affected by the config bits.

Edit: Now we have your configuration bits available, I can confirm it:

#pragma config POSCMOD = HS // Primary Oscillator Configuration (HS osc mode)
#pragma config OSCIOFNC = ON // CLKO Output Signal Active on the OSCO Pin (Enabled)
#pragma config FSOSCEN = ON // Secondary Oscillator Enable (Enabled)
#pragma config JTAGEN = ON // JTAG Enable (JTAG Port Enabled)

All those being on, or not set specifically to disabled, will be overriding any and all other functions on those pins.

Electronic – MPLAB XC8 + PIC18 + external memory = Error 712 (can’t generate code for this expression)

I was just having a play around with this and it seems like something you should report to Microchip but I have found a workaround that might be useful in the interim. The problem only seems to occur with multi-byte variables outside an array or when trying to access the first element of an array. The following code compiles OK and seems to generate plausible assembler output although I didn't have a chip with external RAM to test:

#include <xc.h>
#include <stdio.h>
#include <stdint.h>

far uint8_t intVariable;
far int intArray[1000];

void main(void) {
    intVariable = 1;
//    intArray[0] = 3; <<- Causes an error
    intArray[1] = 3;
    intArray[999] = 3;
    printf("%d\n", intVariable);
    printf("%d\n", intArray[1]);
}

I suspect based on that it tries to perform some optimization on writing to a multi-byte variable that falls down, but when inside an array it generates the full code to calculate the offset that seems to work OK. Note that I only have the free compiler so the pro edition may optimize out the constant array access, but I'd imagine changing the index to a variable would fix that if it does happen.

When I compared my compiler / linker options to yours under the XC8 compiler optimizations I also had to enable "Instruction Invariant Mode" for it to work. Hopefully that might get you up and running and it might be a good additional test case to submit to Microchip.

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Electronic – PIC32 Peripheral Pin Select for Digital Output

Electronic – MPLAB XC8 + PIC18 + external memory = Error 712 (can’t generate code for this expression)

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