| 摘要 |
The scannable RS latch has inputs which are responsive to inverse SET and RESET signals and two outputs for providing two complementary signals. The latch includes a first multiplexer which responds to a first set of control signals for selectively passing inverse SET and RESET signals, or signal SCANIN to an output of the first multiplexer. A first latch responds to a clock signal for storing a logic value of a signal appearing at the output of the first multiplexer, and has two inputs and two outputs, the inputs of the first latch being coupled to the output of the first multiplexer. A second latch responds to the clock signal for storing logic values of signals appearing at the two outputs of the first latch, and has two inputs and two outputs. The inputs of the second latch are coupled to the outputs of the first latch, and the outputs of the second latch provide two complementary output signals. The first output of the second latch provides a SCANOUT signal. A second multiplexer within the second latch alternately places the scannable RS latch in a normal mode operation and a test mode operation. |
