RCVDL56DPFL/SP, RCV56DPFL/SP, and RCV336DPFL/SP Designer’s Guide
6-8
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6.5 EQM AVERAGING
A host-programmable EQM averaging feature helps the host controller with retrain and rate change decisions. A single-pole
low-pass filter is used to average the EQM samples. The number of symbol intervals between EQM samples is host-
programmable in memory location 26Bh (EQMBaudInterval). Also, the host can program the number of EQM samples to be
used before the final filtered EQM value (FilteredEQM) is determined. The EQMAT bit is set if this final FilteredEQM
(address 26Fh) is larger than the EQMAT threshold (address 133h). If EQMBaudInterval is 0, then the EQM averaging is
disabled as is by default. Suitable values for addresses 26Bh and 26Ch are 20h and 64h, respectively. They may be altered
as desired. The value obtained at address 26Fh is the same as if the host were to read and average the MSB of EQM read
at address 20Ch (Function 46). All RAM accesses are 8-bit.
Parameter Name
Address
(Hex)
Default
Value
Description
EQM Baud Interval
26B
0
Symbols between EQM samples used as input to LPF.
Num EQM Samples
26C
0
EQM samples to be run through the EQM LPF.
Saved Filtered EQM
26F
Output of EQM filter used for EQMAT determination (MSB value).
Summary of Contents for RC336DPFL
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