I need to use 4-5 8-pin PICs to operate as slaves to an Atmel AVR acting as I2C master. These must share the bus with an I2C FRAM (100kHz, 400kHz, 1MHz) and an I2C RTC (ST M41T81S 400kHz only).

Can the PICs (12F683 or 12F615 probably) handle a 400kHz clock?