E-5
INSTRUCTION SET SUMMARY
SUB = Subtract
register from register 0 0 1 0 1 0 d w mod reg r/m 2 2
register from memory 0 0 1 0 1 0 0 w mod reg r/m 7** 7** b h
memory from register 0 0 1 0 1 0 1 w mod reg r/m 6* 6* b h
immediate from
register/memory 1 0 0 0 0 0 s w mod 101 r/m immediate data 2/7** 2/7** b h
immediate from accu-
mulator (short form) 0 0 1 0 1 1 0 w immediate data 22
SBB = Subtract with borrow
register from register 0 0 0 1 1 0 d w mod reg r/m 2 2
register from memory 0 0 0 1 1 0 0 w mod reg r/m 7** 7** b h
memory from register 0 0 0 1 1 0 1 w mod reg r/m 6* 6* b h
immediate from
register/memory 1 0 0 0 0 0 s w mod 0 1 1 r/m immediate data 2/7** 2/7** b h
immediate from accu-
mulator (short form) 0 0 0 1 1 1 0 w immediate data 22
DEC = Decrement
register/memory 1 1 1 1 1 1 1 w reg 0 0 1 r/m 2/6 2/6 b h
register (short form) 0 1 0 0 1 reg 2 2
CMP = Compare
register with register 0 0 1 1 1 0 d w mod reg r/m 2 2
memory with register 0 0 1 1 1 0 0 w mod reg r/m 5* 5* b h
register with memory 0 0 1 1 1 0 1 w mod reg r/m 6* 6* b h
immediate with
register/memory 1 0 0 0 0 0 s w mod 1 1 1 r/m immediate
data 2/5* 2/5* b h
immediate with accu-
mulator (short form) 0 0 1 1 1 1 0 w immediate
data 22
NEG = Change sign 1 1 1 1 0 1 1 w mod 0 1 1 r/m 2/6* 2/6* b h
AAA = ASCII adjust for
addition 0 0 1 1 0 1 1 1 44
AAS = ASCII adjust for
subtraction 0 0 1 1 1 1 1 1 44
DAA = Decimal adjust
for addition 0 0 1 0 0 1 1 1 44
DAS = Decimal adjust for
subtraction 0 0 1 0 1 1 1 1 44
Table E-1. Instruction Set Summary (Sheet 4 of 19)Instruction Format
Clock Count Notes
Real
Ad-
dress
Mode
or
Virtual
8086
Mode
Pro-
tected
Virtual
Ad-
dress
Mode
Real
Ad-
dress
Mode
or
Virtual
8086
Mode
Pro-
tected
Virtual
Ad-
dress
Mode