The ADC0851 and ADC0858 are 2 and 8 input analog data acquisition systems They can function as conventional multiple input A D converters automatic scanning A D converters or programmable analog ``watchdog'' systems In ``watchdog'' mode they monitor analog inputs and determine whether these inputs are inside or outside user programmed window limits This monitoring process takes place independent of the host processor When any input falls outside of its programmed window limits an interrupt is automatically generated which flags the processor the chip can then be interrogated as to exactly which channels crossed which limits