AMD-K6 Datasheet, PDF (40/346 Pages) Advanced Micro Devices – AMD-K6 Processor

AMD-K6^® Processor Data Sheet
Preliminary Information
20695H/0—March 1998
AL (low order bits). The same naming convention applies to
EBX, ECX, and EDX. EDI, ESI, ESP, and EBP can be used as
smaller 16-bit registers called DI, SI, SP, and BP respectively,
but these registers do not have 8-bit versions. Figure 6 shows the
EAX register with its name components, and Table 3 lists the
dwo rd ( 3 2 b i t s ) g e n e ra l -p u rp o s e re g i s t e rs a n d t h e i r
corresponding word (16 bits) and byte (8 bits) versions.
31
16 15
87
0
EAX
AX
AH
AL
Figure 6. EAX Register with 16-Bit and 8-Bit Name Components
Table 3. General-Purpose Register Dword, Word, and Byte Names
32-Bit Name
(Dword)
EAX
EBX
ECX
EDX
EDI
ESI
ESP
EBP
16-Bit Name
(Word)
AX
BX
CX
DX
DI
SI
SP
BP
8-Bit Name
8-Bit Name
(High-order Bits) (Low-order Bits)
AH
AL
BH
BL
CH
CL
DH
DL
–
–
–
–
–
–
–
–
22
Software Environment
Chapter 3