PMC-Sierra, Inc.
PRELIMINARY
PM5381 S/UNI-2488
DATASHEET
PMC-2000489
ISSUE 1
SATURN USER NETWORK INTERFACE FOR 2488 MBIT/S
state transition can take place. When OUTDATA is a logic one, the clock difference detector
must fail 39 consecutive times before the state transition can occur.
OUTLOCK:
The clock difference detector DROPPING OUT OF DATA transition configuration bit
determines the number of times the clock difference detector must pass before the CRU
control state machine transitions from the LOCKED TO DATA state to the DATA IN RANGE
state. When OUTLOCK is a logic zero, the clock difference detector must fail once before the
state transition can occur. When OUTLOCK is a logic one, the clock difference detector must
fail 39 consecutive times before the state transition can occur.
TRAIN:
The CRU reference training status indicates if the CRU is locking to the reference clock or the
locking to the receive data as described in TBD. TRAIN is a logic one if the CRU is locking or
locked to the reference clock. TRAIN is a logic zero if the CRU is locking or locked to the
receive data. TRAIN is invalid if the CRU is not used.
FILL_LEVEL[3:0]:
The FIFO Fill level sets the amount of data that must be accumulated in the FIFO before valid
data is output to the system. The level ensures that enough data is in the FIFO to prevent an
underflow condition caused by jitter on the input clock. The default value is set to 48 or one
half of the FIFO’s total capacity of 96 words.
LOS_COUNT[3:0]:
The Loss of signal 1’s/0’s transition detector count. This field sets the value for the number of
consecutive all-zeros or all-ones pattern that will force the CRU out of the LOCK TO DATA
state. Each bit in the binary count represents 8 ones or zeros in the pattern. I.e. to set the
consecutive all-ones or all-zeros pattern to 128 the LOS_COUNT should be set to “10000”b.
The default value for this field is 128.
Proprietary and Confidentail to PMC-Sierra Inc., and for its Customer’s Internal Use
126
PMC [ PMC-SIERRA, INC ]
