The mode, RT address, and data structures can be either initialized by the host processor or automatically initialized at power-on. Jumpers and an on-board EEPROM select the settings and provide data for initialization. The host can reprogram the contents of the EEPROM. For critical applications, a PROM may be used in place of the EEPROM. Fast autoinitialization enables the PM1553-1 to respond to 1553 command words on the databus even before the host processor has finished booting.
The PM1553-1 is available with up to four input and two output discretes. The input discretes are factory-configured to the desired circuit and threshold voltage. A variety of series and shunt configurations (open/ground, voltage/ground, and voltage/open) are available. In addition to analog filtering, inputs are debounced through a programmable digital circuit. Each input discrete may be programmed to issue a service request on the positive and/or negative edge the input signal. Output discretes are under host control and have open-collector circuits with optional pull-up resistors.
The Downloads section contains data sheets with complete information for PM1553-1 product.