signal diagram of 8085

                      

Signal diagram of 8085

all signal are classified into six groups:-

address bus

1. data bus
2. control and status signal 
3. power supply and frequency signals
4. External initiated
5. Serial input-output signals

full description of groups

address and data buses:-

       1.   address buses are of 16 bits  A0-A15 which are divide into two-part

                lower order address bus A0-A7 and higher-order address buses A8-A15.

       2. address bus has unidirectional.

      

        3. data bus are 5-bits (D0-D7).

        4. multiplexed address and data buses are AD0-AD7.

        

 control and status signal:-

      the control signal is control  ALE, RDbar, WRbar, IO\Mbar, status signal.

   ALE:-

               it is used to enable address latch.

               it indicates whether bus functions data bus or address bus.

               if ALE=1 then the bus function as the address bus.  

               if ALE=0then bus function data bus.

  status signals:-

            S1              S0             operations

                 0                   0                                    hold

                 0                   1                                    write

                 1                   0                                    read  

             1               1                               fetch

Externally initiated or interrupt signals:-

externally initiated or interrupt signals

externally initiated or interrupt signals