MCP23016 Question

[mychangl]

After using MCP23016 for quite sometime, at last i discovered something unusual.
I have been using 2 MCP23016 differentiate by the address to 1 PIC. The task is very easy, read from 1 unit and display to another unit. The code works fine. The circuit works fantastic.
Until one day i accidentally break the SDA line ( point A in the schematic ). All LED at the display unit all goes OFF except LEDs connected to GP0.1 and GP1.1. The same scenario happen if the point B is break. I tried different approach in programming and wiring but the results is similar. S0me how GP0.1 and GP1.1 activated.

Can anyone explain.

Thank you..

[Electrosolve]

I don't know much about this device but if you disconnect the i2c data or clock connections, the output latches will contain the values from where the communication stops. Without seeing the program I'm not sure why it always stop with the GP0.1 and GP1.1 latched.

RS