The 74FR900 is a data bus multiplexer routing any of three 9-bit ports to any other one of the three ports. Readback of data latched from any port onto itself is also possible. The 74FR900 maintains separate control of all latch-enable, output enable and select inputs for maximum flexibility. PINV allows inversion of the data from the C8 to A8 or B8 path. This is useful for control of the parity bit in systems diagnostics.