xrt94l33 Exar Corporation, xrt94l33 Datasheet - Page 461

• Manufacturer Part Number: xrt94l33
• Description: Multi-channel, Multi-function Device Aggregates 3 Ds3/e3/sts-1 Into Oc3/stm-1
• Manufacturer: Exar Corporation

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3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
Figure 120 presents a timing diagram that illustrates the behavior of various “Receive UTOPIA Interface
block” signals, during the “Multi-PHY” UNI Device Selection and Read operation.
Figure 120 Timing Diagram of the Receive UTOPIA Data and Address Bus signals, during the “Multi-
PHY” UNI Device Selection and Write Operations
Notes regarding Figure 120:
The Receive UTOPIA Data bus is configured to be 16 bits wide. Hence, the data, which the Receive UTOPIA Interface
The Receive UTOPIA Interface Block is configured to handle 54 bytes/cell. Hence, Figure 94 illustrates the ATM Layer
In Figure 120, the ATM Layer processor is initially reading ATM cell data from the Receive UTOPIA Interface
within UNI #2 (RxUAddr[4:0] = 0x03). However, the ATM Layer processor is also polling the Receive
UTOPIA Interface block within UNI #1 (RxUAddr[4:0] = 0x01) and some “non-existent” device at
RxUAddr[4:0] = 0x1F. The ATM Layer processor completes its reading of the cell from UNI #1 at clock edge
block places on the Receive UTOPIA Data bus, is expressed in terms of 16-bit words (e.g., W0 - W26).
processor reading 27 words (e.g., W0 through W26) for each ATM cell.
Begin reading ATM cell data into “Selected” UNI
1. Assert RxUEnB*
2. Read in the first byte/word of ATM cell from the
“Receive Utopia Data Bus & check for the asserted
RxUSoC signal.
RxUData[15:0]
Poll all UNIs within the “Multi-PHY” System.
Determine which UNIs contain ATM cell data
that needs to be read.”
Select “Available” UNI
1. Apply UTOPIA Address of the “selected” Receive
UTOPIA Interface block onto the “UTOPIA Address”
bus.
2. Negate the RxUEnB* signal
RxUAddr[4:0]
RxUEnB*
Check the RxUClav level while reading
in the last byte (word) of the current
cell..
RxUClk
RxUClav
RxUSoC
Continue to read in ATM Cell data
W23
01h
1
START
Cell Received from 03h
01h
1Fh
W24
2
W25
03h
3
03h
W26
1Fh
4
01h
5
461
01h
Yes
No
W0
03h
6
Cell Received from 01h
wish to read more
03h
Layer processor
1Fh
cells from the
W1
“selected”
the ATM
7
Does
UNI?
Yes
01h
W2
8
RxUClav
“High”
01h
03h
W3
Is
?
Wait for RxUClav to toggle “high”
Yes
9
03h
W4
1Fh
10
No
RxUClav
“High”
Is
03h
?
W5
11
03h
01h
W6
12
XRT94L33
No
Rev.1.2.0.