The µPD72042 is a microcomputer peripheral LSI device for IEBus protocol control.
The µPD72042 performs all the processing required for layers 1 and 2 of the IEBus. The devices incorporate large
transmission and reception buffers, allowing the microcomputer to perform IEBus operations without interruption.
They also contain an IEBus driver and receiver, allowing them to directly connected to the bus directly.

FEATURES
● Control of layers 1 and 2 of the IEBus protocol
   • Support of a multi-master scheme
   • Broadcast function
  • Two communication modes having different transmission speeds can be selected.

Transmission speed
Mode 0 Approx. 3.9 Kbps
Mode 1 Approx. 17 Kbps

● Built-in IEBus driver and receiver
● Transmission and reception buffers
   Transmission buffer : 33 bytes, FIFO
   Reception buffer : 40 bytes, FIFO (capable of holding more than one frame of reception data.)
● Microcomputer interface
Three-/two-wire serial I/O, Transfer starting with MSB
● Program crashes can be detected by means of a watchdog timer.
● Low power consumption (standby mode): 50 µA (max)
● Oscillator frequency (fX): 6 MHz
  • frequency accuracy: ±1.5%
● Operating voltage: 5 V ±10%