Please define the external interrupt in pic16f84

[d@nny]

Hello!
I have read about interrupts in pic16f84. I can understand the four interrupts in the PORTB RB4 to RB7. But i cant understand the external interrupt on RB0. Why it is called external?

 

[wp100]

Hi,

Good question... cannot give you a specific answer, though expect there might be some reason for it, suspect its an old term carried over from earlier chips, as you say RB4-7 are as much Externals as RB0 , just that RB0 is edge triggered.

Looking at the 18F Interrupt datasheet it quotes -
For external interrupt events, such as the RB0/INT0 pin or PORTB change interrupt, the interrupt....
So think this confirms the point.

As well as the specific chips datasheet there are the 16 Family and 18 Family Reference Datasheets from Microchip which expand on many points.
However its widely accepted that they are terrible manuals for the beginner to learn from, perhaps use them in conjuction with some of the free online tutorials.