XRT7245
DS3 UNI FOR ATM
á
PRELIMINARY
REV. 1.03
110
3.3.2.105
Tx CP Idle Cell Payload Register
This “Read/Write” byte-field allows the user to specify
the contents of the payload portion of the Idle Cells
that are to be generated by the Transmit Cell Processor.
The default value of this byte is 5Ah.
Note:
The payload portion of each Idle Cell will consist of
contents of this register, replicated 48 times.
3.3.2.106
UTOPIA Configuration Register
This register allows the user to control many aspects
of the operation of the Transmit UTOPIA Interface. The
description of each of these bit-fields follows.
Bit 5—Handshake Mode
This “Read/Write” bit-field allows the user to configure
the Transmit and Receive UTOPIA Interface blocks to
operate in either the “Octet Level” or “Cell Level”
Handshake Modes.
Writing a “0” to this bit-field configures both the
Transmit and Receive UTOPIA Interface blocks to op-
erate in the “Octet-Level” Handshake Mode. Writing a
“1” to this bit-field configures both of these blocks to
operate in the “Cell Level” Handshake Mode.
For more information on “Octet-Level” and “Cell-Level”
Handshake Mode operations, please see Sections
6.1.2.2.1.1 and 6.1.2.2.1.2.
Bit 4—M-PHY/S-PHY* (UTOPIA Operating Mode)
This “Read/Write” bit-field allows the user to configure
the UNI chip to operate in either the Single-PHY or
Multi-PHY modes. When the UNI chip is operating in
Single PHY Mode, it is configured such that the ATM
Layer Processor will be writing ATM cell data to and
reading ATM cell data from it, and no other UNI ICs.
Consequently, in Single PHY Mode, the UNI IC will
not be checking for a valid Address on the UTOPIA
Address Bus. It will simply support read and write
operations, from the ATM Layer Processor, based
upon the UTOPIA Data Bus signal (e.g., TxEnB,
TxSoC, TxClav, RxEnB).
When the UNI chip is operating in Multi-PHY Mode, it
is now configured such that the ATM Layer Processor
will be writing ATM cell data to and reading ATM cell
data from it and, possibly numerous other UNI ICs.
Therefore, in this mode, the UNI IC will be checking
for a valid Address, on the UTOPIA Address bus, prior
to performing any reads or writes from the ATM Layer
Processor. Unless the UNI IC detects it own Address,
on the UTOPIA Address bus, it will ignore the UTOPIA
Data Bus signals (e.g, TxEnB, TxSoC, TxClav, RxEnB).
Writing a “1” to this bit-field will configure the UNI to
operate in the Multi-PHY mode. Writing a “0” to this
bit-field will configure the UNI to operate in the Single-
PHY mode. This configuration selection applies to
both the Transmit UTOPIA Interface and Receive
UTOPIA Interface blocks. The default UTOPIA
Operating Mode is Multi-PHY.
For more information on Single-PHY and Multi-PHY
operation, please see Sections 6.1.2.3 and 7.4.2.2.2.
Bit 3—CellOf52Bytes
This “Read/Write” bit-field allows the user to configure
the Cell Size (e.g., Number of octets per cell) that the
Transmit and Receive UTOPIA Interface blocks will
Address = 69h, Tx CP Idle Cell Payload Register
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Tx Idle Cell Pattern—Payload Byte
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
1
1
0
1
0
1
0
Address = 6Ah, UTOPIA Configuration Register
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Unused
Hand Shake
Mode
MPHY/
SPHY*
CellOf
52 Bytes
TxFIFO
Depth[1]
TxFIFO
Depth[0]
UTOPIA
Width 16
RO
RO
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
1
0
0
0
0