|Opcode||Operand||Explanation of Instruction
|NOP||none||No operation||No operation is performed. The instruction is fetched and decoded. However no operation is executed.
|HLT||none||Halt and enter wait state||The CPU finishes executing the current instruction and halts any further execution. An interrupt or reset is necessary to exit from the halt state.
The interrupt enable flip-flop is reset and all the interrupts except the TRAP are disabled. No flags are affected.
The interrupt enable flip-flop is set and all interrupts are enabled. No flags are affected. After a system reset or the acknowledgement of an interrupt, the interrupt enable flipflop is reset, thus disabling the interrupts. This instruction is
|RIM||none||Read interrupt mas||
This is a multipurpose instruction used to read the status of interrupts 7.5, 6.5, 5.5 and read serial data input bit. The instruction loads eight bits in the accumulator with the following interpretations.
|SIM||none||Set interrupt mask||
This is a multipurpose instruction and used to implement the 8085 interrupts 7.5, 6.5, 5.5, and serial data output. The instruction interprets the accumulator contents as follows.