IOC on pin going HIGH and LOW

[richard]

followed by a 74HC14,

why the redundant extra schmitt trigger?

in the pic 16F1885x family all input pins are ST by default unless you clear the INPUT THRESHOLD CONTROL bit in the INLVLx register

[Demon]

why the redundant extra schmitt trigger? ...

Because I started development using a 16F1937 and didn't notice the ST on the 16F18877.

(runs over to the datasheet)



EDIT: Wow! That PIC is amazing; every pin has ADC and ST. That's gonna help bring costs down from those 74HC14 ICs.

[richard]

Because I started development using a 16F1937

unfortunately one of the very few enhanced core pic chips without INPUT THRESHOLD CONTROL.

[Ioannis]

193x was a nice chip in its time but now comparing to 188xx seems so old...!

And I have many in stock...

Ioannis

[Demon]

Registers associated with Interrupts are in Table 7-1 on p. 153:




From my observations, you need 2 entries in the DEFINES for 16F:

- Result bit,
- Enable bit.


#DEFINE {DT-INT interrupt NAME} {result flag REGISTER}, {result flag bit}, {enable bit REGISTER}, {enable bit}

For example:
#DEFINE IOC_INT PIR0,IOCIF, PIE0,IOCIE

[Demon]

I keep the IOC flags right alongside the pin definitions (this is a EC11-type rotary encoder; 2 shafts + pushbutton):

;--- Setup pins ----------------------------------------------------------------

COM1_MHz_WiperA             var PortA.2         ' Outer
IOC_COM1_MHz_WiperA_flag    var IOCAF.2         '       IOC flag
COM1_MHz_WiperB             var PortA.3         ' Outer
IOC_COM1_MHz_WiperB_flag    var IOCAF.3         '       IOC flag
COM1_KHz_WiperA             var PortA.0         ' Inner
IOC_COM1_KHz_WiperA_flag    var IOCAF.0         '       IOC flag
COM1_KHz_WiperB             VAr PortA.1         ' Inner
IOC_COM1_KHz_WiperB_flag    var IOCAF.1         '       IOC flag
COM1_SPST                   var PortA.4         ' Swap
IOC_COM1_SPST_flag          var IOCAF.4         '       IOC flag

It makes it easier (for me) to make sure things are connected exactly where I think they are. It's also much easier to move things about on the pins.