HI-35981

The HI-35981 from Holt Integrated Circuits interfaces up to eight ARINC 429 receive buses to a high-speed Serial Peripheral Interface (SPI) enabled microcontroller. The device is an enhanced version of Holt’s well-established HI-35980 (HI-3598) family, with additional features and functionality. The user-programmable label filtering capability has been expanded from 16 labels to all 256 labels, and the 4-word deep receive FIFO has been increased to 32 words deep.

Also, a 32-word deep transmit FIFO has been added, significantly increasing the transmit capability from the single-word buffer on the existing device. The digital transmit channel has a digital output pin to set the data rate on an external line driver, such as Holt’s lightning-protected HI-8597 or galvanically isolated HI-8598.

Each channel has an on-chip analog line receiver. Two choices of receiver input are available for each channel, each with different input resistance values to provide flexibility when using external lightning protection circuitry. Receive FIFO status can be monitored using the programmable external interrupt pins, or by polling the status register. Other features include the ability to switch the bit-signifiance of the ARINC 429 label and to recognize the 32nd received ARINC bit as either data or a parity flag. The SPI and all control signals are CMOS and TTL compatible and support 3.3V or 5V operation.