OVERVIEW OF THE 80C186 FAMILY ARCHITECTURE

LAHF S Z U A U P U C

SAHF 7 6 5 4 3 2 1 0

PUSHF POPF

U U U U O D I T S Z U A U P U C

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

U = Undefined; Value is indeterminate

O = Overflow Flag

D = Direction Flag

I = Interrupt Enable Flag

T = Trap Flag

S = Sign Flag

Z = Zero Flag

A = Auxiliary Carry Flag

P = Parity Flag

C = Carry Flag

A1014-0A

Figure 2-11. Flag Storage Format

2.2.1.2Arithmetic Instructions

The arithmetic instructions (see Table 2-4) operate on four types of numbers:

Unsigned binary

Signed binary (integers)

Unsigned packed decimal

Unsigned unpacked decimal

2-19

Page 48
Image 48
Intel 80C188XL, 80C186XL user manual Lahf S Z U a U P U C, Sahf 7 6 5 4 3 2 1, Pushf Popf U U O D I T S Z U a U P U C