Latch

A 8 bit  latch comprises of transparent latch D flip  flop. It is commonly  used  to interface output  device with  microprocessor. A typical example of such 8 bit  latch 74LS373 is shown in figure.

The devices  includes  eight  D latches with tri  buffers  only on eis shown in figure for clarity 8 input lines ( ID to 8D)  are connected to data bus and 8  output  lines  to output devices. The  enable signal is connected to clock ( LK). The  enable signal  is actives  high,  when it goes high data are latched from data bus. The  output  control  signal  is active low and  it enables the tri state buffers to output  data to output  devices.

The concept  of interfacing microprocessor with  output  device will be one  more clear after  reading chapter7.