VSC8150QQ 查看數據表（PDF） - Vitesse Semiconductor
零件编号
产品描述 (功能)
生产厂家
VSC8150QQ Datasheet PDF : 20 Pages
| |||
VITESSE
SEMICONDUCTOR CORPORATION
Preliminary Data Sheet
VSC8150
2.488Gb/s SONET/SDH
Overhead Monitor
Table 1: Frame Detection Select Settings
Function
24 bits
48 bits
12 bits
Frame detection disabled
SELFRDET1
1
0
0
1
SELFRDET0
0
1
0
1
Figure 2: Frame Detection Patterns
48 bits
24 bits
12 bits
A1 (0xF6)
A1 (0xF6)
A1 (0xF6)
A2 (0x28)
A2 (0x28)
A2 (0x28)
Loss of Signal
A Loss of Signal (LOS active high) input is provided to prevent noise from propagating into the overhead
output logic. Logic zeros will be clocked into the device when LOS is active high, and SEF will be immediately
synchronously asserted, with LOF appearing 3ms afterward. If RXSCLKIN+/- disappears before LOS is
asserted the part will freeze and SEF/LOF will never appear.
Loss of Frame
A Loss of Frame (LOF) defect is declared (RXLOF active high) when a Severely Errored Frame (SEF)
condition persists for 3ms (R6-59). The LOF state detection is based on an integrating timer to prevent sporadic
errors from not asserting LOF, such as a periodic 1ms error. In the event of sporadic errors, the out of frame
timer increments when RXSEF = 1. It is on hold when RXSEF = 0 and does not change state as long as this
condition lasts for < 3 ms. The out of frame timer is reset to it’s initial state if the RXSEF is low for > 3 ms, and
an LOF defect is cancelled after an in-frame condition (RXSEF low) persists for a total of 3ms (R6-61).
Multiple SONET/SDH Rate Functionality
The VSC8150 supports three SONET/SDH rates: STS-48/STM-16, STS-12/STM-4, and STS-3/STM-1.
The user is responsible for rate-provisioning the device by setting the two inputs RATESEL[1:0] (See Table 2).
The device requires a clock rate appropriate to the selected data rate in order for internal circuitry to function
correctly. LOF integration timing is 3ms regardless of the rate selected.
G52186-0, Rev. 3.0
10/12/98
© VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
Page 3
Share Link: 