L64724 LSI Logic Corporation, L64724 Datasheet - Page 29

• Manufacturer Part Number: L64724
• Description: Satellite Receiver
• Manufacturer: LSI Logic Corporation

1. Serial Mode is the recommended interface mode. LSI Logic does not recommend parallel
mode for new designs.
ASn
CSn
D[7:0]
DTACK/POL
Microcontroller Interface
Address Strobe
The ASn signal is an active-LOW address strobe input.
The L64724 latches the address on the A[2:0] signals on
the falling edge of the ASn signal.
Chip Select
The CSn signal is an active-LOW chip select strobe input.
During a read cycle, the microcontroller must assert CSn
(LOW) to access the on-chip data registers. The
microcontroller must latch the data from the L64724 on
the rising edge of CSn. During a write cycle, CSn must
be asserted prior to data being valid from the microcon-
troller to the L64724. After the data has met the minimum
setup time, the microcontroller deasserts CSn (HIGH) to
strobe the data. There is a minimum write time to allow
for internal synchronization. Setup and hold times are
measured with respect to the falling edge of CSn.
Data
The D[7:0] signals form the bidirectional data bus, which
is an input data bus when data is written to the L64724
chip and a data output bus when the L64724 chip is read
in Parallel Host Interface mode
HIGH). The data lines are 3-stated when not being read
or written. When Serial Host Interface mode is selected
(HOST_MODE pin LOW), D[0] is used as the Serial
Clock (SCLK) signal to synchronize the transfer of serial
data on the Serial Data (SDATA) pin. In Serial Host
interface mode, XCTR_OUT[1] functions as SDATA, D[1]
is used as the SDATA signal to transfer serial data, and
D[3:2] are used as the two LSBs of the L64724 slave
address.
Data Acknowledge/Wait Polarity
The DTACK/POL signal determines the polarity of the
Data Acknowledge/Wait Signal. When the DTACK/POL
signal is LOW, DTACKn/WAIT is active-LOW. When the
DTACK/POL signal is HIGH, the DTACKn/WAIT signal is
active-HIGH.
1
(HOST_MODE pin
Bidirectional
Input
Input
Input
2-9