Multi-Precision

This table indicates the number of clock periods for the multi-precision instructions. The number of clock periods includes the time to fetch both operands, perform the operations, store the results and read the next instructions. The number of read and write cycles is shown in parenthesis as (r/w).

The headings have the following meanings:

Dn = Data register operand.
M = Memory register operand.

Multi-Presicion Instruction Execution Times

Instruction Size op Dn, Dn op M, M
 ADDX  byte,word  4 ( 1 / 0 )  18 ( 3 / 1 )
       long  8 ( 1 / 0 )  30 ( 5 / 2 )
 CMPM  byte,word  –  12 ( 3 / 0 )
       long  –  20 ( 5 / 0 )
 SUBX  byte,word  4 ( 1 / 0 )  18 ( 3 / 1 )
       long  8 ( 1 / 0 )  30 ( 5 / 2 )
 ABCD      byte  6 ( 1 / 0 )  18 ( 3 / 1 )
 SBCD      byte  6 ( 1 / 0 )  18 ( 3 / 1 )