IDT77V1054L25PF IDT, Integrated Device Technology Inc, IDT77V1054L25PF Datasheet - Page 15

• Manufacturer Part Number: IDT77V1054L25PF
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of IDT77V1054L25PF

• Data Rate: 25.6/51.2Mbps
• Number Of Channels: 4
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (max): 3.6V
• Operating Temp Range: 0C to 70C
• Package Type: TQFP
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Not Compliant

DIAGNOSTIC FUNCTIONS
1. LOOPBACK
loopback mode is controlled via bits 1 and 0 of the Diagnostic Control
Registers:
Normal Mode
data to be transmitted is transferred to the TC, where it is queued
and formatted for transmission by the PMD. Receive data from the
PMD is decoded along with its clock for transfer to the receiving
"upstream system".
IDT77V1054
Quad Port ATM PHY for 25.6 and 51.2 Mbps with 8-bit Utopia 2
There are two loopback modes supported by the 77V1054. The
This mode, Figure 12, supports normal operating conditions:
Bit 1
ATM Layer
0
1
1
ATM Layer
Device
Device
Bit 0
Interface
0
0
1
Utopia
Interface
Utopia
Normal operating mode
PHY Loopback
Line Loopback
MODE
TC sublayer
TC sublayer
Figure 13. PHY Loopback
Figure 12. Normal Mode
3505 tbl 12
6.42
15
PHY Loopback
connection within the PHY from the transmit PHY-ATM interface to the
PHY-ATM receive interface. Note that while this mode is operating, no
data is forwarded to or received from the line interface.
Line Loopback
for a means to test the overall system, including the line. Since this
mode will 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.
As Figure 13 illustrates below, this loopback mode provides a
Figure 14 might also be called “remote loopback” since it provides
PMD sublayer
PMD sublayer
Preliminary
77v1054 drw 34
Interface
77v1054 drw 33
Interface
Line
Line