21

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Index 53h-5Ah

Internal use, do not overwrite

Index 5Bh

Decode Control Register 2 (R/W)

Reset Value = 00h

7

Internal use, do not overwrite.

6

Reserved — Set to 0.

5

BIOS ROM Positive Decode — Selects positive or subtractive decoding for accesses to the configured ROM

space:

0 = Subtractive; 1 = Positive.

4

Internal use, do not overwrite.

3

Internal use, do not overwrite.

2

Internal use, do not overwrite.

1

Internal use, do not overwrite.

0

Internal use, do not overwrite.

Note: Positive decoding by the PC87200 speeds up the I/O cycle time.

Index 5Ch-FFh

Internal use, do not overwrite

Table 4. Bridge Configuration Registers (Continued)

Bit

Description