Question

Explain the conditional CALL instructions of Intel 8085.

Answer 1

Conditional Call : In conditional call, the subroutine is called only if the condition is satisfied. In the conditional call, following procedure is followed, if the condition is true.

Format:

`[[SP] - 1] ← [PC_H]`

`[[SP] - 2] ← [PC_L]`

`[SP] ← [SP] - 2`

`[PC] ← addr`

The conditional call instructions and conditions are as listed below:

1) CC addr : Call if carry (Cy = 1)

2) CNC addr :  Call if no carry (Cy = 0)

3) CZ addr : Call if zero (Z = 1)

4) CNZ addr : Callif no zero (Z = 0)

5) CP addr : Call if plus (S = 0)

6) CM addr : Call if minus (S = 1)

7) CPO addr : Call if odd parity (P = 0)

8) CPE addr : Call if even parity (P = 1)