Panasonic MN101C77C, F77G user manual Pin Setup, SC4ODC0, SC4ODC1

Chapter 13 Serial Interface 4

„Busy Flag

This serial interface contains 2 busy flags (SLVBSY, I2CBSY).

The SLVBSY flag is set to "1" when address transmitted from master matches with the slave address. The I2CBSY flag is set to "1" during communication on IIC bus.

In 10 bits addresss mode, if the upper 2 bits address which is first to be transmitted from master matches with the I2CAD9-8 of the SC4AD1 register, the SLVBSY flag is set to "1" and SC4IRQ is not generated. If the lower 8 bits address which is next to be transmitted from master matches with the I2CAD7-0 of the SC4AD0 register, the SLVBSY flag is remained to "1" and SC4IRQ is generated. If these address mis- match, the SLVBSY flag is cleared to "0" and SC4IRQ is not generated.

„Bus Line Monitor

Bus line can be monitored during the general call communicaation.

For monitoring, while the SELI2C flag is set to "1", set the I2CGEM flag of the SC4AD1 register to "1" and set the direction control of the communication pin to input. Though serial 4 interrupt is generated at this time, it does not output signal to the data and clock, and thus, has no effect on the communicaiton.

„Pin Setup

Table 13-3-1 shows pin setup (SDA, SCL pins) for serial interface 4 data transmission.

N-ch open drain setup is always necessary for using this serial interface. Use the pull-up resistor control register (PnPLU) of each port for pull-up resistor setup. Input/output of the transfer data is automatically switched.

Table 13-3-1	Pin Setup
Item		Data I/O pin	Clock I/O pin
Port pin		SDA pin	SCL pin
		P01	P02
Function		P53	P54
Nch open-drain control register		SC4ODC0
		SC4ODC1
Pull-up resistor control register		P0PLU
		P5PLU

Note that this serial interface does not features the functions which resets the serial interface circuit on determination of reception data or change the slave address. Always use the soft- ware for determination of reception data incuding in the general call communication mode.

XIII - 10 Operation