AMIS-52100 Datasheet, PDF (20/26 Pages) AMI SEMICONDUCTOR – Transceiver with Clock and Data Recovery

AMIS-52100 Low-Power Transceiver with Clock and Data Recovery
Data Sheet
Table 26: Auto Slice Control Registers
Auto Slice Control Registers
Register (HEX) Name
0x0a
DATA SLICE
THRESHOLD
0x0f
HYSTERESIS
AUTOSLICE
Bits States Comments
All
Set a fixed reference level for the slice output to be
compared to in the DAC mode
0,1
00
0mV hysteresis used in the threshold circuit
01
20mV hysteresis used in the threshold circuit
10
50mV hysteresis used in the threshold circuit
11
100mV hysteresis used in the threshold circuit
2,3
00
DAC mode used for data detection (DEFAULT)
01
Average mode used for data detection
10
Peak mode used for data detection
11
DAC mode used for data detection
9.6 Data and Clock Recovery
Data recovered in a noisy environment or from a small RF signal usually is jittery. The AMIS-52100 can remove much of that data jitter
by recovering a synchronous clock signal from the incoming data. The AMIS-52100 can be set to do auto slice data detection. The
clock and data recovery circuits can be programmed to generate a data clock for synchronously clocking the data out of the AMIS-
52100, removing much of the jitter in this process. The AMIS-52100 has an internal PLL that must be programmed to the frequency of
the data by setting the values in the FWORD register and setting the coefficients of the filter. If these values are close to the data rate,
the AMIS-52100 will recover the data clock from the incoming detected data. The CDR circuit can also be set or clamped with a
tolerance to the frequency difference between the supposed data rate and the actual data rate to improve the performance of the CDR
function. The CDR circuit can be set to reset after a programmed number of data time periods without data. This stop check function
allows the CDR circuit to reacquire the clock when new data is received, maintaining better clock to data synchronization.
Table 27 presents the registers associated with the data and clock recovery function. Refer to the AMIS application note “Clock and
Data Recovery Circuit Operation and Setup” for more information.
AMI Semiconductor – Rev 4.0, Mar. 06 – M-20535-004
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