Datasheet

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DP83849C
7.3.4 TDR Window Register (TDR_WIN), Page 2, address 17h
This register contains sample window control for the Time Domain Reflectometry (TDR) cable diagnostics. The two val-
ues contained in this register specify the beginning and end times for the window to monitor the response to the transmit-
ted pulse. Time values are in 8ns increments. This provides a method to search for multiple responses and also to
screen out the initial outgoing pulse.
7.3.5 TDR Peak Register (TDR_PEAK), Page 2, address 18h
This register contains the results of the TDR Peak Detection. Results are valid if the TDR_CTRL[11] is clear following
sending the TDR pulse.
7.3.6 TDR Threshold Register (TDR_THR), Page 2, address 19h
This register contains the results of the TDR Threshold Detection. Results are valid if the TDR_CTRL[11] is clear follow-
ing sending the TDR pulse.
Table 46. TDR Window Register (TDR_WIN), address 17h
Bit Bit Name Default Description
15:8 TDR_START 0, RW TDR Start Window:
Specifies start time for monitoring TDR response.
7:0 TDR_STOP 0xFF, RW TDR Stop Window:
Specifies stop time for monitoring TDR response. The Stop Win-
dow should be set to a value greater than or equal to the Start Win-
dow.
Table 47. TDR Peak Register (TDR_PEAK), address 18h
Bit Bit Name Default Description
15:14 RESERVED 0, RO RESERVED: Writes ignored, read as 0.
13:8 TDR_PEAK 0, RO TDR Peak Value:
This register contains the peak value measured during the TDR
sample window. If Min Mode control (TDR_CTRL[7]) is 0, this con
-
tains the maximum detected value. If Min Mode control is 1, this
contains the minimum detected value.
7:0 TDR_PEAK_TIME 0, RO TDR Peak Time:
Specifies the time for the first occurrence of the peak value.
Table 48. TDR Threshold Register (TDR_THR), address 19h
Bit Bit Name Default Description
15:9 RESERVED 0, RO RESERVED: Writes ignored, read as 0.
8 TDR_THR_MET 0, RO TDR Threshold Met:
This bit indicates the TDR threshold was met during the sample
window. A value of 0 indicates the threshold was not met.
7:0 TDR_THR_TIME 0, RO TDR Threshold Time:
Specifies the time for the first data that met the TDR threshold.
This field is only valid if the threshold was met.