Intel 80C186XL, User Manual

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OVERVIEW OF THE 80C186 FAMILY ARCHITECTURE
2-4
During periods when the Execution Unit is busy executing instructions, the Bus Interface Unit
sequentially prefetches instructions from memory. As long as the prefetch queue is partially full,
the Execution Unit fetches instructions.
2.1.3 General Registers
The 80C186 Modular Core family CPU has eight 16-bit general registers (see Figure 2-3). The
general registers are subdivided into two sets of four registers. These sets are the data registers
(also called the H & L group for high and low) and the pointer and index registers (also called the
P & I group).
Figure 2-3. General Registers
15
Data
Group
0 8 7
H L
AX
BX
CX
DX
AH AL
BH
CH
DH
BL
CL
DL
SP
BP
SI
DI
Accumulator
Base
Count
Data
Stack Pointer
Base Pointer
Source Index
Destination Index
Pointer
and
Index
Group
A1033-0A