Dynamically selectable polarity latch.

摘要

A selective true or complement storage latch includes a data input switch (62, 72) having an input node (61) connecting to a binary bit input source (D), a control input (62') for accepting a first or second control state, a first data output node (65) which is selectively connected to the data input node (61) when the control input )62') is in the first state and a second data output node (70) which is selectively connected to the data input node (61) when the control input (72') is in the second state. There is also a first inverting gate (64) having an input connected to the first data output (65) of the data input switch (62) and an output connected to a first storage node (66). A second inverting gafe (74) has an input connected to the first storage node (66) and an output connected to the second storage node (76), the input of the second inverting gate (74) being connected to the second output (70) of the data input switch (72), the output of the second inverting gate (74) being connected to the input of the first inverting gate (64). The data input node (61) is selectively connected to the input of the first inverting gate (64) through the first output (65) of the data input switch (62) when the control input (62') is in a first state and the data input node (61) is selectively connected to the input of the second inverting gate (74) through the second output (76) of the data input switch (72) when the control input (72') is in the second state. In this manner the true value of the data at 'the data input node (61) is stored in the latch when the I control input is in the first state and the complement of the data at the data input node (61) is stored in the latch when the control input is in the second state.