XRT72L52 Datasheet, PDF (30/480 Pages) Exar Corporation – TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

XRT72L52
TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.3
áç
PRELIMINARY
PIN DESCRIPTION
PIN #
89
PIN NAME
MOTO
90
CS
91
WR_R/W
92
ALE_AS
93
NC
94
A(0)
95
A(1)
96
A(2)
97
A(3)
98
A(4)
99
A(5)
100
A(6)
101
A(7)
102
A(8)
TYPE
I
I
I
I
DESCRIPTION
Motorola/Intel Processor Interface Select Mode:
This input pin allows the user to configure the Microprocessor Interface
to interface with either a "Motorola-type" or "Intel-type" microprocessor/
microcontroller. Tying this input pin to VCC, configures the microproces-
sor interface to operate in the Motorola mode (e.g., the Framer device
can be readily interfaced to a "Motorola type" local microprocessor).
Tying this input pin to GND configures the Microprocessor Interface to
operate in the Intel Mode (e.g., the Framer device can be readily inter-
faced to a “Intel type" local microprocessor).
Chip Select Input:
This active-low input signal selects the Microprocessor Interface Sec-
tion of the Framer device and enables READ/WRITE operations
between the Local Microprocessor and the Framer on-chip registers
and RAM locations.
Write Data Strobe (Intel Mode):
If the microprocessor interface is operating in the Intel Mode, then this
active-low input pin functions as the WR (Write Strobe) input signal from
the µP. Once this active-low signal is asserted, then the Framer will latch
the contents of the µP Data Bus, into the addressed register (or RAM
location) within the Framer IC. In the Intel Mode, data gets latched on
the rising edge of WR
R/W Input Pin (Motorola Mode):
When the Microprocessor Interface Section is operating in the Motorola
Mode, then this pin is functionally equivalent to the R/W pin. In the
Motorola Mode, a READ operation occurs if this pin is at a logic "1".
Similarly, a WRITE operation occurs if this pin is at a logic "0".
Address Latch Enable/Address Strobe:
This input is used to latch the address (present at the Microprocessor
Interface Address Bus, A(9:0)) into the Framer Microprocessor Interface
circuitry and to indicate the start of a READ/WRITE cycle. This input is
active-high in the Intel Mode (MOTO = "low") and active-low in the
Motorola Mode (MOTO = "high").
I
See Description for Pin 103
I
See Description for Pin 103
I
See Description for Pin 103
I
See Description for Pin 103
I
See Description for Pin 103
I
See Description for Pin 103
I
See Description for Pin 103
I
See Description for Pin 103
I
See Description for Pin 103
11