Download the 74F521 datasheet PDF.
This datasheet also includes the 74F521MSA variant, as both parts are published together in a single manufacturer document.
Note: The manufacturer provides a single datasheet file (74F521MSA_NationalSemiconductor.pdf) that lists specifications for multiple related part numbers.
The ’F521 is an expandable 8-bit comparator It compares two words of up to eight bits each and provides a LOW output when the two words match bit for bit The expansion input IA e B also serves as an active LOW enable input
