Set Direction Flag
|
86/88 |
Y |
186 |
Y |
286 |
Y |
386 |
Y |
486 |
Y |
STD |
|
Ovfl |
N |
Dir |
1 |
Int |
N |
Trap |
N |
Sign |
N |
Zero |
N |
Aux |
N |
Prty |
N |
Carry |
N |
STD sets the Direction Flag. No other flags are affected. Setting the
direction flag causes string operations to decrement SI and DI.
------------------------------------ Timing ----------------------------------
OpCode Instruction 386 286 86
FD STD 2 2 2
------------------------------------ Logic -----------------------------------
DF = 1
See Also CLD STC CLC CMC STI CLI CMPS Flags |