What does mean I2C Firmware controlled Master operation, Slave is IDLE
To put it into a better perspective, the line in question is a part of the list of I2C modes that PIC1672 supports.  Here's the full list:



"I2C Firmware controlled Master operation" means that the SSP in this PIC can be configured as an I2C bus master.  The contents of the I2C transactions in this mode will be defined by firmware (which slave device to talk to and when, what to send, what to receive) .

"Slave is IDLE" means that the PIC doesn't act as an I2C slave in this mode.