INTRODUCTION
This board demonstrates the features of the HI‐8429 eight input discrete sensor IC. The HI‐8429 is powered from 3.3V ±5% VLOGIC and 12 to 16.5V VDD supply voltages. The device is configured and sensor data read by the SPI serial bus, sensor input thresholds are set by writing to the four on chip DACs. Note in this document the references made to Airbus sensor levels are referring to the levels specified in the Airbus specification ABD0100H. This EVM (Evaluation Module) contains a 16 bit, Freescale MC9S12XDT512 MCU, this is used to interface to a terminal emulator and control the HI‐8429. The Holt CD, included with the evaluation kit, contains example source code, providing an easy path for the customer to develop their own control software. A Serial UART output from the MCU provides debug and data messages to be sent to a PC using any terminal emulation program such as Tera Term. The HI‐8429 Evaluation Board is shown in the picture below; two HI‐8429 devices are mounted on the board so the customer can evaluate SPI daisy chain operation.