Intel 80C186XL PCB Relocation Register, Relreg, Relocates the PCB within memory or I/O space

Models: 80C186XL 80C188XL

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PCB Relocation Register

PERIPHERAL CONTROL BLOCK

Register Name:

PCB Relocation Register

Register Mnemonic:

RELREG

Register Function:

Relocates the PCB within memory or I/O space.

15

ES T L

M E M

R

R

R

R

1

1

1

1

9

8

7

6

 

 

 

 

R

R

R

R

1

1

1

1

5

4

3

2

 

 

 

 

0

R

R

R

R

1

1

9

8

1

0

 

 

 

 

 

 

A1262-0A

Bit

Bit Name

Reset

Function

Mnemonic

State

 

 

 

 

 

 

ET

Escape Trap

0

If ET is set, the CPU will trap when an ESC

 

 

 

instruction is executed.

 

 

 

 

SL

Slave/Master

0

If SL is set, the Interrupt Control Unit operates in

 

 

 

slave mode. If SL is clear, it operates in master

 

 

 

mode.

 

 

 

 

MEM

Memory I/O

0

If MEM is set, the PCB is located in memory

 

 

 

space. If MEM is clear, the PCB is located in I/O

 

 

 

space.

 

 

 

 

R19:8

PCB Base

0FFH

R19:8 define the upper address bits of the PCB

 

Address

 

base address. All lower bits are zero. R19:16 are

 

Upper Bits

 

ignored when the PCB is mapped to I/O space.

 

 

 

 

NOTE: Reserved register bits are shown with gray shading. Reserved bits must be written to a logic zero to ensure compatibility with future Intel products.

Figure 4-1. PCB Relocation Register

4-2

Page 131
Image 131
Intel 80C186XL, 80C188XL PCB Relocation Register, Relreg, Relocates the PCB within memory or I/O space, Register Name