User Guide.
HI-8475 Evaluation Board.
The Holt HI-8475 Evaluation Board demonstrates features of the HI-8475 ARINC 429 receiver IC. This device will decode 32 bit ARINC 429 words into parallel or serial format without the use of any software. The board and the HI-8475 can be run from a single 3.3V+/- 5% supply voltage. The HI-8475 and EVM (Evaluation Module) requires no software for control; all functions are set by hardware switches. Data can be filtered according to the label content of the ARINC word, using the LLA and FILT input setting and set with DIP switches. Other DIP switches configure the device speed, test modes etc.
If the PARITY pin is set high (see schematic), the receiver logic checks for odd parity. ARINC bit 32 is overwritten by the HI-8475 to a zero if odd parity was received, or to a one if even parity (error condition) was received. Regardless of parity error, the word is stored in the input shift register. If this is undesirable, the user should select the ADK-8477, which disgards words with parity error when parity checking is enabled. If parity checking is disabled (PARITY pin = logic "0"), all 32 bits of the ARINC word are stored without parity check.
