T8207 Datasheet, PDF (50/158 Pages) Agere Systems – ATM Interconnect

CelXpres T8207
ATM Interconnect
Advance Data Sheet
September 2001
9 UTOPIA Interface (continued)
9.6 UTOPIA Pin Modes
In multi-PHY mode, the T8207 interfaces with up to 32 PHY ports. Each port is numbered and accessed using a
certain combination of the cell available/enable (Clav/Enb*) and address (Addr) signals. The addr_clav_en bits in
the main configuration 2 register (address 0112h) are used to select this combination of cell available/enable and
address signals. Table 16 indicates the port numbering for each of the possible configurations.
The first selection of zero address and four cell available/enable signals (a value of “000” in bits 2:0 of register
0112h) is used for connection to UTOPIA level one devices. Use this selection to connect from one to four PHY
devices to the T8207 in ATM mode. If only one PHY is connected, any of the four cell available signals may be con-
nected to the PHY. For two PHY devices, connect any two (internal port number must be matched to the clav being
used). All unused u_rxclav inputs require connection to ground. Four queues are allocated per PHY in this configu-
ration.
The second selection of one address and four cell available/enable signals (a value of “010” in bits 2:0 of register
0112h) is used for connection to UTOPIA level two devices. The selection may be used for up to four PHY groups
of two ports each. (See Appendix 1 of The ATM Forum Technical Committee UTOPIA Level 2, Version 1.0 specifi-
cation.) All unused u_rxclav inputs require connection to ground. Four queues are allocated per PHY in this config-
uration.
The third selection of two address and four cell available/enable signals (a value of “101” in bits 2:0 of register
0112h) is used for connection to four UTOPIA level 2 PHY groups of four ports each. If the T8207_sel bit in register
0112h is set, four queues are allocated per PHY. If the T8207_sel bit is cleared, two queues are allocated per PHY
if the normal 16-port mode described in Section 11.4, Queuing is used or a programmable number of queues can
be allocated per PHY based on the settings in registers 017Ch—017Eh.
The fourth selection of two address and two cell available/enable signals (a value of “100” in bits 2:0 of register
0112h) is used for connection to two UTOPIA level 2 PHY groups of four ports each. All unused u_rxclav inputs
require connection to ground. Four queues are allocated per PHY in this configuration.
The fifth selection of three address and two cell available/enable signals (a value of “111” in bits 2:0 of register
0112h) is used for connection to two UTOPIA level 2 PHY groups of eight ports each. All unused u_rxclav inputs
require connection to ground. If the T8207_sel bit in register 0112h is set, four queues are allocated per PHY. If the
T8207_sel bit is cleared, two queues are allocated per PHY if the normal 16-port mode described in Section 11.4,
Queuing is used or a programmable number of queues can be allocated per PHY based on the settings in registers
017Ch—017Eh.
The sixth selection of three address and one cell available/enable signals (a value of “110” in bits 2:0 of register
0112h) is used for connection to eight UTOPIA level 2 PHY ports. All unused u_rxclav inputs require connection to
ground. Four queues are allocated per PHY in this configuration.
The seventh selection of four address and one cell available/enable signals (a value of “001” in bits 2:0 of register
0112h) is used for connection to sixteen UTOPIA level 2 PHY ports. All unused u_rxclav inputs require connection
to ground. If the T8207_sel bit in register 0112h is set, four queues are allocated per PHY. If the T8207_sel bit is
cleared, two queues are allocated per PHY if the normal 16-port mode described in Section 11.4, Queuing is used
or a programmable number of queues can be allocated per PHY based on the settings in registers 017Ch—017Eh.
Finally, the eighth selection of four address and two cell available/enable signals (a value of “011” in bits 2:0 of reg-
ister 0112h) is used for connection to two UTOPIA Level 2 PHY groups of 16 ports each. All unused u_rxclav inputs
require connection to ground. The T8207_sel bit in register 0112h must be set to ‘1’ for this mode. Two queues are
allocated per PHY, if the normal 32-port mode described in Section 11.4, Queuing is used or a programmable
number of queues can be allocated per PHY based on the settings in registers 0178h—017Eh.
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