Write-acknowledge circuit comprising a write detector and a bistable element for four-phase handshake signalling

摘要

The write-acknowledge circuit 1 comprises a write detector 2 and a bistable element 3. The write detector of circuit 1 according to the invention comprises two switch elements (21, 22 or 23, 24) connected in series unlike the prior-art write detector which comprises 10 switch elements. The write detector 2 further has two write inputs 4 and 5, two complementary inputs 11 and 12, and acknowledge output 6. The complementary inputs are coupled to the control inputs of the series-connected switch elements and the acknowledge output 6 is formed by the connecting part of the switch elements. The write signals on write inputs 4, 5 encode a 1-bit variable according to the Double-Rail Encoding method, using four-phase handshake signalling for the write signals.;The two write inputs of write detector 2 also form the two inputs of the bistable element 3. The bistable element 3 has two outputs 7 and 8 coupled crosswise to the complementary inputs of write detector 2 in order to energize acknowledge output 6 through the complementary inputs of the write detector 2 in response to a write signal on one of the two write inputs 4, 5. The acknowledge signal on acknowledge output 6 denotes that the write signal has been processed by circuit 1 and the write signal is now allowed to change value.