The SN74ALS819 and SN74ALS29818 are 8-bit pipeline registers each with an on-chip shadow register. They are for use in applications such as write control store and shadow register diagnostics. The output registers of the 'ALS819 and 'ALS29818 are loaded in parallel from either the I/O port (DQ0 DQ7) or the shadow register. The shadow register of the 'ALS2981A 8 can be loaded serially or from either the I/O port (Y0 Y7) or the pipeline register. The 'ALS819 shadow register can be loaded serially or from the I/O port (DQ0 DQ7). In addition, the 'ALS819 provides a Parity-Even (PE) output, which monitors parity of the output register. Operation of these devices is controlled by the Mode and SDI inputs as shown in the function table.