VSC7216-02
Data Sheet
(Unconditional)
Invalid
Valid
Invalid
Invalid
Valid
Invalid
0
1
2
3
4
Valid
Valid
Misaligned
Comma
Figure 12. State Diagram of the Invalid Transmission Counter
Link Status Outputs
The receiver ERRn, KCHn and IDLEn outputs indicate status for each channel as shown in Table 9. Because this
status is encoded, multiple conditions can occur simultaneously; therefore, the states are prioritized as indicated
(1 being highest priority). For example, if both Out-of-Band and Disparity Errors occur, only an Out-of-Band Error is
reported because it has higher priority.
The ERRn, KCHn and IDLEn status signals apply to the data on Rn[7:0] on a per-character basis. The only exception
to this is the Underrun/Overrun indication, which is asserted coincident with the duplicated character when an
underrun occurs, and is asserted following the deleted character (on the cycle where the deleted character should have
appeared, for example) when overrun occurs.
Table 9. Receiver Status Signals
ERRn
KCHn
IDLEn
Priority Link Status
Valid Data Transmission: A valid 10B data character with correct disparity was
received. The correctly decoded version of this character is on Rn[7:0].
0
0
0
7
1
Underrun/Overrun Error: The elastic buffer has not been able to add/drop an IDLE
when required. Data on Rn[7:0] is invalid.
0
0
0
1
1
0
Kxx.x Special Character Detected (not IDLE): A valid 10B special character with
correct disparity was received. The correctly decoded version of this character, per
Table 4, is on Rn[7:0].
6
IDLE Detected: A valid IDLE character (K28.5) with correct disparity was received.
The correctly decoded version of this character, per Table 4, is on Rn[7:0].
0
1
1
1
1
1
0
0
1
1
1
0
1
0
1
5
3
4
2
2
Out-of-Band Error Detected: A character was received that was not a valid 10B
data or control character. Data on Rn[7:0] is invalid.
Disparity Error Detected: A valid 10B character was received that did not have the
expected disparity. Rn[7:0] is invalid.
Loss of Synchronization: The receiver state machine is in the Loss-of-Sync state.
Data on Rn[7:0] is invalid.
RESYNC: The receiver state machine is in the Re-Synchronization state. Data on
Rn[7:0] is a decoded version of K28.1, K28.5 or K28.7.
18 of 40
G52367 Revision 4.2
December 2006
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
