HI-8282A

The 16-bit parallel data bus exchanges the 32-bit ARINC data word in two steps when either loading the transmitter or interrogating the receivers. The data bus interfaces with CMOS and TTL. Timing of all the circuitry begins with the master clock input, CLK. For ARINC 429 applications, the master clock frequency is 1 MHz. Each independent receiver monitors the data stream with a sampling rate 10 times the data rate. The sampling rate is software selectable at either 1MHz or 125KHz. The results of a parity check are available as the 32nd ARINC bit. The HI-8282A examines the null and data timings and will reject erroneous patterns. For example, with a 125KHz clock selection, the data frequency must be between 10.4KHz and 15.6KHz.

The transmitter has a First In, First Out (FIFO) memory to store 8 ARINC words for transmission. The data rate of the transmitter is software selectable by dividing the master clock, CLK, by either 10 or 80. The master clock of HI-8282A is used to set the timing of the ARINC transmission within the required resolution.