
18
x r
PRELIMINARY
E3 UNI FOR ATM
XRT7234
REV. P1.0.0
12
REQB
O
Receive Equalization Bypass Control output pin—(to be connected
to the XR-T7295E E3 Line Receiver IC).
This output pin is intended to be connected to the REQB input pin of the
XR-T7295E E3 Line Receiver IC. The user can control the state of this
output pin by writing a ‘0’ or ‘1’ to Bit 5 (REQB) within the Line Interface
Driver Register (Address = 84h). If the user commands this signal to toggle “high”
then it will cause the incoming E3 line signal to “by-pass” equalization circuitry,
within the XR-T7295E Device. Conversely, if the user commands this output
signal to toggle “l(fā)ow”, then the incoming E3 line signal with be routed
through the equalization circuitry. For information on the criteria that should be
used when deciding whether to bypass the equalization circuitry or not,
please consult the “XR-T7295E E3 Integrated Line Receiver” data sheet.
Writing a “1” to Bit 5 of the Line Interface Drive Register (Address = 84h)
will cause this output pin to toggle “high”. Writing a “0” to this bit-field will
cause this output pin to toggle “l(fā)ow”.
Note:
If the customer is not using the XR-T7295E E3 Line Receiver IC,
then he/she can use this output pin for a variety of other purposes.
10
13
D9
I/O
Bi-directional Data bus (Microprocessor Interface Section):
This pin
is inactive if the Microprocessor Interface block is configured to operate
over an 8 bit data bus. (Please see description for D15)
11
14
D8
I/O
Bi-directional Data bus (Microprocessor Interface Section):
This pin
is inactive if the Microprocessor Interface block is configured to operate
over an 8 bit data bus. (Please see description for D15)
12
15
VDD
***
Power Supply Pin
13
16
D7
I/O
Bi-directional Data bus (Microprocessor Interface Section):
(Please
see description for D15)
14
17
D6
I/O
Bi-directional Data bus (Microprocessor Interface Section):
(Please
see description for D15)
15
18
D5
I/O
Bi-directional Data bus (Microprocessor Interface Section):
(Please
see description for D15)
16
19
D4
I/O
Bi-directional Data bus (Microprocessor Interface Section):
(Please
see description for D15)
17
20
Width16
I
Microprocessor Interface Block Data Bus Width Selector:
This input
pin allows the user configure the microprocessor interface, of the UNI, to
operate over either an 8 or 16 bit wide data bus. Tying this pin to VCC
configures the Microprocessor Interface Data Bus width to be 16 bits.
Tying this pin to GND configures the Microprocessor Interface Data Bus
width to be 8 bits.
18
21
D3
I/O
Bi-directional Data bus (Microprocessor Interface Section):
(Please
see description for D15)
PIN DESCRIPTION (CONTINUED)
Pin
No.
100 Pin Package
Pin No. 160
PinPackage
Symbol
Type
Description