XRT7245
DS3 UNI FOR ATM
á
PRELIMINARY
REV. 1.03
14
36
RxPOH
O
Receive PLCP Frame Path Overhead (POH) Byte Serial Output Port—Output Pin:
This output pin, along with RxPOHClk, RxPOHFrame, and RxPOHIns pins comprise
the “Receive PLCP Frame POH Byte” serial output port. For each PLCP frame that is
received by the Receive PLCP Processor, this serial output port will output the con-
tents of all 12 POH (Path Overhead) bytes. The data that is output via this pin, is
updated on the rising edge of the RxPOHClk output clock signal. The RxPOHFrame
pin will pulse “high” when the first bit of the Z6 byte is being output on this output pin.
37
A8
I
Address Bus Input (Microprocessor Interface)—MSB (Most Significant Bit):
This
input pin, along with inputs A0 - A7 are used to select the on-chip UNI register and
RAM space for READ/WRITE operations with the “l(fā)ocal” microprocessor.
38
RxPOHClk
O
Receive PLCP Frame Path Overhead (POH) Byte Serial Output Port
—
Output
Clock Signal:
This output clock pin, along with RxPOH, RxPOHFrame, and RxPO-
HIns pins comprise the “Receive PLCP Frame POH Byte” serial output port. All POH
data that is output via the RxPOH pin, is updated on the rising edge of this clock signal.
39
A7
I
Address Bus Input (Microprocessor Interface):
(Please see description for A8)
40
RxPO-
HFrame
O
Receive PLCP Frame Path Overhead (POH) Byte Serial Output Port—Beginning
of Frame Signal Pin:
This output pin, along with RxPOH, RxPOHClk, and RxPOHIns
pins comprise the “Receive PLCP Frame POH Byte” serial output port. This output pin
provides framing information to external circuitry receiving and processing this POH
(Path Overhead) data, by pulsing “high” when the first bit of the Z6 byte is output via the
RxPOH output pin. This pin is “l(fā)ow” at all other times during this PLCP POH framing
cycle.
Note:
The “Receive PLCP Frame POH Byte” Serial Output Port is available for the 160
pin packaged device.
41
A6
I
Address Bus Input (Microprocessor Interface):
(Please see description for A8)
42
A5
I
Address Bus Input (Microprocessor Interface):
(Please see description for A8)
43
A4
I
Address Bus Input (Microprocessor Interface):
(Please see description for A8)
44
A3
I
Address Bus Input (Microprocessor Interface):
(Please see description for A8)
45
A2
I
Address Bus Input (Microprocessor Interface):
(Please see description for A8)
46
A1
I
Address Bus Input (Microprocessor Interface):
(Please see description for A8)
47
RxGFCMSB
O
Received GFC Nibble Field—MSB Indicator
: This output pin functions as a part of
the “Receive GFC-Nibble Field” Serial Output port; which also consists of the RxGFC
and RxGFCClk pins. This pin pulses “high” the instant that the MSB (Most Significant
Bit) of a GFC Nibble is being output on the RxGFC pin.
48
A0
I
Address Bus Input (Microprocessor Interface)—LSB (Least Significant Bit):
(Please see description for A8)
49
RxGFClk
O
Received GFC Nibble Serial Output Port Clock Signal:
This output pin functions as
a part of the “Receive GFC Nibble-Field” Serial Output Port; also consisting of the
RxGFC and RxGFCMSB pins. This pin provides a clock pulse which allows external
circuitry to latch in the GFC Nibble-Data via the RxGFC output pin.
Note:
The “Receive GFC Nibble Field” serial output port is only available for the 160
pin packaged devices.
50
RxClk
I
Receive UTOPIA Interface Clock Input:
The byte (or word) data, on the Receive
UTOPIA Data bus is updated on the rising edge of this signal. The Receive UTOPIA
Interface can be clocked at rates up to 50 MHz.
PIN DESCRIPTION (CONT’D)
P
IN
N
O
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S
YMBOL
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YPE
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ESCRIPTION