DS21354/DS21554 3.3V/5V E1 Single-Chip Transceivers
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Signal Name:
RD
(
DS
)
Signal Description:
Read Input—Data Strobe
Signal Type:
Input
In Intel Mode,
RD
determines when data is read from the device. In Motorola Mode,
DS
is used to write
to the device. See the
Bus Timing Diagrams
section.
Signal Name:
CS
Signal Description:
Chip Select
Signal Type:
Input
Must be low to read or write to the device.
CS
is an active-low signal.
Signal Name:
ALE (AS)/A7
Signal Description:
Address Latch Enable (Address Strobe) or A7
Signal Type:
Input
In nonmultiplexed bus operation (MUX = 0), serves as the upper address bit. In multiplexed bus
operation (MUX = 1), serves to demultiplex the bus on a positive-going edge.
Signal Name:
WR
(R/
W
)
Signal Description:
Write Input (Read/Write)
Signal Type:
Input
WR
is an active-low signal.
