I2C总线扩展器

I2C总线扩展器：This application note describes two PLD designs made with the PLC42VA12. Both designs are controller functions for an I2C-bus n-bit I/O expander. The first design is
a controller function for a n-bit I2C-bus Input Expansion (I2C-bus Slave Transmitter
function) and the second one for a n-bit I2C-bus Output Expansion (I2C-bus Slave
Receiver function).The I2C-bus is a 2-way, 2-line communication
between different ICs or modules. The two lines are a serial data line (SDA) and a serial
clock line (SCL). The designs provide remote
input or output expansion for our Philips
micro controller families via the two-line serial
bidirectional I2C-Bus. The I2C-Bus slave
address of the designs is equal to the
address of the PCF8574 (remote 8-bit I/O expander). The I2C-Bus has been specified for 100kHz, but the PLC42VA12 designs can go up to 1MHz. This makes the designs suitable as test vehicle for the new fast I2C-Bus standard of 400 kHz.