XRT75L06 Datasheet, PDF (46/63 Pages) Exar Corporation – SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR

XRT75L06
REV. 1.0.3
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
6.1 THE MICROPROCESSOR INTERFACE BLOCK SIGNALS
The LIU may be configured into different operating modes and have its performance monitored by software
through a standard microprocessor using data, address and control signals. These interface signals are de-
scribed below in Table 12. The microprocessor interface can be configured to operate in Asynchronous mode
or Synchronous mode.
PIN NAME
Pmode
D[7:0]
Addr[7:0]
CS
RD
WR
RDY
INT
RESET
TABLE 12: XRT75L06 MICROPROCESSOR INTERFACE SIGNALS
TYPE
DESCRIPTION
I Microprocessor Interface Mode Select Input pin
This pin is used to specify the microprocessor interface mode.
I/O Bi-Directional Data Bus for register "Read" or "Write" Operations.
I Eight-Bit Address Bus Inputs
The XRT75L06 LIU microprocessor interface uses a direct address bus. This address bus is
provided to permit the user to select an on-chip register for Read/Write access.
I Chip Select Input
This active low signal selects the microprocessor interface of the XRT75L06 LIU and enables
Read/Write operations with the on-chip register locations.
I Read Signal This active low input functions as the read signal from the local µP. When this
pin is pulled “Low” (if CS is “Low”) the LIU is informed that a read operation has been
requested and begins the process of the read cycle.
I Write Signal This active low input functions as the write signal from the local µP. When this
pin is pulled “Low” (if CS is “Low”) the LIU is informed that a write operation has been
requested and begins the process of the write cycle.
O Ready Output This active low signal is provided by the LIU device. It indicates that the cur-
rent read or write cycle is complete, and the LIU is waiting for the next command.
O Interrupt Output This active low signal is provided by the LIU to alert the local mP that a
change in alarm status has occured. This pin is Reset Upon Read (RUR) once the alarm sta-
tus registers have been cleared.
I Reset Input This active low input pin is used to Reset the LIU.
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