Datasheet

DP83849IF
SNOSAX8D –JUNE 2009–REVISED APRIL 2013 www.ti.com
10.3.10 Link Quality Data Register (LQDR), Page 2
This register provides read/write control of thresholds for the 100Mb Link Quality Monitor function. The
register also provides a mechanism for reading current adapted parameter values. Threshold values may
not be written if the device is powered-down.
Table 10-35. Link Quality Data Register (LQDR), address 1Eh
Bit Bit Name Default Description
15:14 RESERVED 0, RO RESERVED: Writes ignored, read as 0.
13 SAMPLE_PARAM 0, RW Sample DSP Parameter:
Setting this bit to a 1 enables reading of current parameter values and initiates
sampling of the parameter value. The parameter to be read is selected by the
LQ_PARAM_SEL bits.
12 WRITE_LQ_THR 0, RW Write Link Quality Threshold:
Setting this bit will cause a write to the Threshold register selected by
LQ_PARAM_SEL and LQ_THR_SEL. The data written is contained in
LQ_THR_DATA. This bit will always read back as 0.
11:9 LQ_PARAM_SEL 0, RW Link Quality Parameter Select:
This 3-bit field selects the Link Quality Parameter. This field is used for sampling
current parameter values as well as for reads/writes to Threshold values. The
following encodings are available:
000: DEQ_C1
001: DAGC
010: DBLW
011: Frequency Offset
100: Frequency Control
8 LQ_THR_SEL 0, RW Link Quality Threshold Select:
This bit selects the Link Quality Threshold to be read or written. A 0 selects the
Low threshold, while a 1 selects the high threshold. When combined with the
LQ_PARAM_SEL field, the following encodings are available {LQ_PARAM_SEL,
LQ_THR_SEL}:
000,0: DEQ_C1 Low
000,1: DEQ_C1 High
001,0: DAGC Low
001,1: DAGC High
010,0: DBLW Low
010,1: DBLW High
011,0: Frequency Offset Low
011,1: Frequency Offset High
100,0: Frequency Control Low
100,1: Frequency Control High
7:0 LQ_THR_DATA 0, RW Link Quality Threshold Data:
The operation of this field is dependent on the value of the Sample_Param bit.
If Sample_Param = 0:
On a write, this value contains the data to be written to the selected Link Quality
Threshold register.
On a read, this value contains the current data in the selected Link Quality
Threshold register.
If Sample_Param = 1:
On a read, this value contains the sampled parameter value. This value will
remain unchanged until a new read sequence is started.
98 Register Block Copyright © 2009–2013, Texas Instruments Incorporated
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