Table 3.15 decode of mad pins, Decode of mad pins – Avago Technologies LSI53C895A User Manual

Page 108

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3-20

Signal Descriptions

MAD[3:1] – These pins are used to set the size of the external
expansion ROM device attached. Encoding for these pins are listed
in

Table 3.15

(“0” indicates a pull-down resistor is attached, “1”

indicates a pull-up resistor is attached).

MAD[0] – This pin is the slow ROM pin. When pulled up, it enables
two extra cycles of data access time to allow use of slower memory
devices.

Note:

All MAD pins have internal pull-down resistors.

Table 3.15

Decode of MAD Pins

MAD[3:1]

Available Memory Space

000

16 Kbyte

001

32 Kbyte

010

64 Kbyte

011

128 Kbyte

100

256 Kbyte

101

512 Kbyte

110

1024 Kbyte

111

no external memory present

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