Hi friends,

In my current project, I try to connect a matrix keyboard to PORTC of
16C73A. The interrupt signal is generated by ORing 4 rows and applied to
RB6. Because PORTC is pulled up internally, I don't worry about the static
status of the keyboard. What I am worrying about now is how to receive the
RB6 interrupt.

After studying the databook of PIC, I found that the interrupt of RB6 is
generated by comparing the current pin level and the last pin level latched.
If they mismatch, the interrupt will occur. And, GBIE and RBIE have some
relationship with this interrupt. RBIF is the flag to indicate the interrupt
has been received. Do you know any other Bits related? And, could you give
any other ideas to solve the problem? (Only interrupt mode is needed. PORTC
is prefered.) Thanks in advance.

Yours sincerely,
Xinhua Rong, BG6CR, China