XRT72L13 Datasheet, PDF (27/370 Pages) Exar Corporation – M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC

áç
PRELIMINARY
PIN DESCRIPTIONS
PIN #
NAME
84
Rd_DS
85
D6
86
A7
87
VDD
88
WR_RW
89
D7
90
A8
91 GND (TEST MODE)
TYPE
I
I/O
I
****
I
I/O
I
****
XRT72L13
M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC
REV. P1.0.6
DESCRIPTION
Read Data Strobe (Intel Mode):
If the microprocessor interface is operating in the Intel Mode, then this
input will function as the RD* (READ STROBE) input signal from the
local mP. Once this active-low signal is asserted, then the Framer will
place the contents of the addressed registers (within the Framer) on
the Microprocessor Data Bus (D[7:0]). When this signal is negated,
the Data Bus will be tri-stated.
Data Strobe (Motorola Mode):
If the microprocessor interface is operating in the Motorola mode,
then this pin will function as the active-low Data Strobe signal.
Bi-directional Data Bus (Microprocessor Interface Section):
Please see description for D7
Address Bus Input (Microprocessor Interface):
(Please see description for A8)
Power Supply Pin
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 mP. Once this active-low signal is asserted, then the Framer
will latch the contents of the mP Data Bus, into the addressed register
(or RAM location) within the Framer IC.
R/W Input Pin (Motorola Mode)
When the Microprocessor Interface Section is operating in the "Motor-
ola 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".
MSB of Bi-Directional Data Bus (Microprocessor Interface Sec-
tion):
This pin, along with pins D0 - D6, function as the Microprocessor
Interface bi-directional data bus, and is intended to be interfaced to
the "local" microprocessor.
Address Bus Input (Microprocessor Interface) - MSB (Most Sig-
nificant Bit):
This input pin, along with inputs A0 - A7 are used to select the on-chip
Framer register and RAM space for READ/WRITE operations with the
"local" microprocessor.
Ground Pin
15