Serial Input / Output data using 8085
8085 Microprocessor has two Serial Input/Output pins that are used to read/write one bit data to and from peripheral devices.
SID (Serial Input Data) line
- There is an One bit Input line inside the 8085 CPU (Pin number 5)
- 1 bit data can be externally read and stored using this SID line
- The data that is read is stored in the A7th bit of the Accumulator
- RIM instruction is used to read the SID line
SOD (Serial Output Data) Line
- There is a One bit Output port inside the 8085 CPU (Pin number 4
- 1 bit data can be externally written in this port.
- To write data into this port, SIM instruction is used.
- The data that is to be written in this port must be stored in the A7th bit of the
Accumulator. - Bit A6 of the Accumulator is known as SOE (Serial output Enable). This bit
Must be set to 1 to enable Serial data output.
