DP83256VF-AP NSC [National Semiconductor], DP83256VF-AP Datasheet - Page 32

• Manufacturer Part Number: DP83256VF-AP
• Manufacturer: NSC [National Semiconductor]

4 0 Modes of Operation
Short Internal Loopback
The Short Internal Loopback mode can be used to test the
functionality of the PLAYER
Clock Recovery function and to test the data paths be-
tween the PLAYER
ring insertion
When in the Short Internal Loopback mode the PLAYER
device performs the following functions
Directs the output data of the Transmitter Block to the
input of the Receiver Block through an internal path
a
device and MACSI devices before
a
device not including the
(Continued)
FIGURE 4-3 Short Internal Loopback
a
32
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
See Figure 4-3 Short 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 – 25
)