| 摘要 |
PURPOSE:To attain both reading and writing operations simultaneously in a simple constitution by providing a means to select and supply data to an optional bit of a shift register with a pointer. CONSTITUTION:Shift registers S10-S43 supply the data on data input terminals I0-I3 and perform the shift operations synchronously with a read signal QRD 16 sent from a queue buffer register. When the write signal QWR is active, the input data on the terminals I0-I3 are written to the registers S10-S43 after the queue pointers P0-P4 are shifted to the left. At the same time, the data on the registers S10-S13 are delivered from output terminals O0-O3. While those queue pointers are shifted to the right when the signal QRD is active. Then all outputs keep their previous states when both signals QWR and QRD are inactive.
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