Figure 2-3 Physical Address Generation

 

 

 

 

Shift

 

 

 

 

 

 

 

 

 

 

 

Left

 

 

 

 

 

 

 

 

 

 

 

4 Bits

 

 

 

 

Segment

 

 

 

 

 

 

1

2

A

4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Base

 

Logical

 

 

 

 

 

 

15

 

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Offset

 

Address

 

 

 

 

 

 

0

0

2

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15

 

 

0

 

 

 

1

2

A

4

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

19

 

 

 

 

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

0

0

2

 

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15

 

 

 

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 2

A 6 2

 

 

 

19

 

0

 

 

 

Physical Address

To Memory

2.3I/O SPACE

The I/O space consists of 64K 8-bit or 32K 16-bit ports. The IN and OUT instructions address the I/O space with either an 8-bit port address specified in the instruction, or a 16-bit port address in the DX Register. Eight-bit port addresses are zero-extended so that A15–A8 are Low. I/O port addresses 00F8h through 00FFh are reserved. The Am186ER and Am188ER microcontrollers provide specific instructions for addressing I/O space.

Figure 2-4 Memory and I/O Space

Memory

Space

1M

I/O

Space

64K

2.4INSTRUCTION SET

The Am186ER and Am188ER microcontrollers use the same instruction set as the 80C186 microcontroller. An instruction can reference from zero to several operands. An operand can reside in a register, in the instruction itself, or in memory. Specific operand addressing modes are discussed on page 2-10.

Table 2-1lists the instructions for the Am186ER and Am188ER microcontrollers in alphabetical order. The Am186™ and Am188™ Family Instruction Set Manual , order #21267, provides detailed information on the format and function of the following instructions.

2-4

Programming

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AMD Am186TMER, Am188TMER user manual I/O Space, Instruction SET