z80:Opcodes:DAA

From Learn @ Cemetech
Revision as of 22:22, 5 February 2016 by Maintenance script (talk | contribs) (Initial automated import)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigationJump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

When this instruction is executed, the A register is BCD corrected using the contents of the flags. The exact process is the following: if the least significant four bits of A contain a non-BCD digit (i. e. it is greater than 9) or the H flag is set, then $06 is added to the register. Then the four most significant bits are checked. If this more significant digit also happens to be greater than 9 or the C flag is set, then $60 is added.

Syntax

   daa

Effects

If the second addition was needed, the C flag is set after execution, otherwise it is reset. The N flag is preserved, P/V is parity and the others are altered by definition.

Uses

T-States

4 t-states

See Also

ADC,ADD,DEC,INC,SBC,SUB