77V126L200TFGI IDT, Integrated Device Technology Inc, 77V126L200TFGI Datasheet - Page 14

• Manufacturer Part Number: 77V126L200TFGI
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of 77V126L200TFGI

• Number Of Channels: 1
• Type Of Atm Phy Interface: UTOPIA
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (max): 3.6V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Pin Count: 64
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

the PMD. Receive data from the PMD is decoded along with its clock for transfer to the receiving "upstream system".
face. Note that while this mode is operating, no data is forwarded to or received from the line interface.
probably be entered under direction from another system (at a remote location), receive data is also decoded and transferred to the upstream system
to allow it to listen for commands. A common example would be a command asking the upstream system to direct the TC to leave this loopback state,
and resume normal operations.
IDT77V126L200
Loopback
There are two loopback modes supported by the 77V126L200. The loopback mode is controlled via bits 1 and 0 of the Diagnostic Control Register:
Normal Mode
Figure 12 shows normal operating conditions: data to be transmitted is transferred to the TC, where it is queued and formatted for transmission by
PHY Loopback
As Figure 13 shows, this loopback mode provides a connection within the PHY from the transmit PHY-ATM interface to the PHY-ATM receive inter-
Line Loopback
Figure 14 might also be called “remote loopback” since it provides for a means to test the overall system, including the line. Since this mode will
ATM Layer
ATM Layer
Device
ATM Layer
Device
Device
Interface
Utopia
Interface
Utopia
Interface
Utopia
0
1
1
Bit 1
TC sublayer
TC sublayer
TC sublayer
Figure 13 PHY Loopback
Figure 14 Line Loopback
Figure 12 Normal Mode
0
0
1
Bit 0
14 of 30
Normal operating mode
PHY Loopback
Line Loopback
Mode
sublayer
PMD sublayer
PMD
PMD sublayer
77v1054 drw 35
77v1054 drw 34
Interface
Interface
77v1054 drw 33
Line
Interface
Line
December 2004
Line