| 摘要 |
PURPOSE:To obtain a microinstruction control circuit that has branching function with a short instruction word length and a fast executing time, by extracting the prescribed data out of the latched parameter group to apply a mask to an extracted parameter and defining the data obtained from masking as an address of the branching destination. CONSTITUTION:A multi-way branch register 200 is connected to a data bus 106 and holds the whole or a part of the contents of the bus 106 when a latch signal WRMBR is produced. A multiplexer 201 selects and delivers the contents MBR of the register 200 according to the value of a selection field (sel) of a multi-branch microinstruction. A multi-branch address generator 202 produces the output of the multiplexer 201 and the address of the branching destination according to a mask field 'mask' and a base field 'base' of the multi-branch microinstruction.
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