Instruction type STC in 8085 Microprocessor

In 8085 Instruction set, STC stands for “SeT the Carry flag”. It sets the cy flag to the 1 state, immaterial of its earlier value. It performs set operation on the cy flag, and the result is stored back in the cy flag.

Mnemonics, Operand Opcode(in HEX) Bytes
STC 37 1

The result of execution of this instruction has been depicted in the following tracing table −

Before After


1 1


0 1

Address Hex Codes Mnemonic Comment
2000 37 STC Set the Cy flag i.e. set Cy=1

The timing diagram against this instruction STC execution is as follows −


Summary − So this instruction STC requires 1-Byte, 1-Machine Cycle (Opcode Fetch) and 4 T-States for execution as shown in the timing diagram.

Updated on: 30-Jul-2019

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