DP83257VF National Semiconductor, DP83257VF Datasheet - Page 33

• Manufacturer Part Number: DP83257VF
• Description: IC FDDI LAYER CTRLR 160PQFP
• Manufacturer: National Semiconductor

Specifications of DP83257VF

• Controller Type: physical layer controller
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 160-BFQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Supply: -
• Interface: -
• Other names: *DP83257VF

4 0 Modes of Operation
Long Internal Loopback
The Long Internal Loopback mode implements the longest
loopback path that is completely within the PLAYER
vice
The Long Internal Loopback mode can be used to test the
functionality of the PLAYER
Recovery function and to test the data paths between the
PLAYER
When in the Long Internal Loopback mode the PLAYER
device performs the following functions
Directs the output data of the Transmitter Block to the
input of the Clock Recovery Module through an internal
path
a
device and MACSI devices before ring insertion
a
device including the Clock
(Continued)
FIGURE 4-4 Long Internal Loopback
a
de-
a
33
The level of the Quiet symbols transmitted through the
PMRD
transmitter off level
If both Short Internal Loopback and Long Internal Loopback
modes are selected Long Internal Loopback mode will
have priority over Short Internal Loopback mode This is the
longest loopback path within the PLAYER
Note that the LILB path is disconnected and should not be
used when the Alternate PMD Interface is active
See Figure 4-4 Long Internal Loopback
Ignores the PMD Data Indicate pins (PMID
Outputs Quiet symbols through the PMD Data Request
pins (PMRD
g
pins during loopback is automatically set to the
g
)
a
device
g
TL F 11708 – 26
)