Avago Technologies LSI53C876E - Manual (Page 90)

3-18 Signal Descriptions
3.3 ROM/Flash Interface Signals
Table 3.14 describes the signals for the ROM/Flash Interface Signals
group.
Table 3.14 ROM/Flash Interface Signals
Name Pin No. Type Strength Description
MAS0/ 190, C8 O 4 mA Memory Address Strobe 0. This pin is used
to latch in the least significant address byte of
an external EPROM or Flash memory. Since
the LSI53C876E moves addresses eight bits at
a time, this pin connects to the clock of an
external bank of flip-flops which are used to
assemble up to a 20-bit address for the
external memory. If an external memory
requires more than 16 bits of addressing as
specified by the pull-down resistors at
power-up and bit 0 in the
Expansion ROM
Base Address register, see the External
Memory Interface diagram for proper usage.
MAS1/ 189, B8 O 4 mA Memory Address Strobe 1. This pin is used
to latch in the address byte corresponding to
address bits [15:8] of an external EPROM or
Flash memory. Since the LSI53C876E moves
addresses eight bits at a time, this pin connects
to the clock of an external bank of flip-flops
which assemble up to a 20-bit address for the
external memory. If an external memory
requires more than 16 bits of addressing as
specified by the pull-down resistors at
power-up and bit 0 in the
Expansion ROM
Base Address register, see the External
Memory Interface diagram for proper usage.
MAD[7:0] 74, 76, 77,
79, 80, 81,
82, 83,
U9, W9, Y9,
V10, Y10,
Y11, W11,
V11 I/O 4 mA Memory Address/Data Bus. This bus is used
in conjunction with the memory address strobe
pins and external address latches to assemble
up to a 20-bit address for an external EPROM
or Flash memory. This bus will put out the least
significant byte first and finishes with the most
significant bits. It is also used to write data to a
Flash memory or read data into the chip from
external EPROM/Flash memory. All MAD pins
have internal pull-up resistors.