HI-35880

The HI-35880 from Holt Integrated Circuits is a silicon gate CMOS device for interfacing a Serial Peripheral Interface (SPI) enabled microcontroller to an ARINC 429 serial bus. It is a drop-in replacement for Holt’s popular HI-3588, with a much improved SPI of 12 MHz. This greatly improves host efficiency over the previous device.

The device provides one receiver with user-programmable label recognition for any combination of 256 possible labels, a 32 by 32 Receive FIFO and an analog line receiver. Receive FIFO status can be monitored using the programmable external interrupt pin, or by polling the HI-35880 Status Register. Other features include the ability to switch the bit-signifiance of ARINC 429 labels. The ARINC input pins are available with different input resistance values to provide flexibility when adding external lightning protection circuitry.

The Serial Peripheral Interface minimizes the number of host interface signals allowing for a small footprint device which can be interfaced to a wide variety of industry-standard microcontrollers supporting SPI. Alternatively, the SPI signals may be controlled using just four general purpose I/O port pins from a microcontroller or custom FPGA. The SPI and all control signals are CMOS and TTL compatible and support 3.3V or 5V operation.

The HI-35880 checks received data against ARINC 429 electrical, timing and protocol requirements. ARINC 429 databus timing comes from a 1 MHz clock input, or an internal counter can derive it from higher clock frequencies having certain fixed values, possibly the external host processor clock.