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AUX – Sensor Controller Registers www.ti.com
17.8.2.9 PRECTL Register (Offset = 20h) [reset = X]
PRECTL is shown in Figure 17-18 and described in Table 17-37.
Prescaler Control The prescaler can be used to count events that are faster than the AUX clock speed. It
can be used standalone or as a start/stop source for the TDC by configuring TRIGSRC.START_SRC and
TRIGSRC.STOP_SRC to TDC_PRE. When counting fast signals with the TDC that are faster than 1/10th
of the clock frequency of AUX it is recommended to use the prescaler.
Figure 17-18. PRECTL Register
31 30 29 28 27 26 25 24
RESERVED
R-X
23 22 21 20 19 18 17 16
RESERVED
R-X
15 14 13 12 11 10 9 8
RESERVED
R-X
7 6 5 4 3 2 1 0
RESET_N RATIO RESERVED SRC
R/W-X R/W-X R-X R/W-1Fh
Table 17-37. PRECTL Register Field Descriptions
Bit Field Type Reset Description
31-8 RESERVED R X
Software should not rely on the value of a reserved. Writing any
other value than the reset value may result in undefined behavior.
7 RESET_N R/W X
Prescaler reset control 0: Prescaler is held in reset 1: Prescaler is
not held in reset
6 RATIO R/W X
Prescaler ratio. This controls how often an event is generated on the
TDC_PRE line. After the prescaler is reset the event output
TDC_PRE is 0.
0h = Prescaler divides by 16. A rising edge on the output is
generated for every 16 rising edges of the input (the output toggles
on every 8th rising edge of the input).
1h = Prescaler divides by 64. A rising edge on the output is
generated for every 64 rising edges of the input (the output toggles
on every 32th rising edge of the input). .
5 RESERVED R X
Software should not rely on the value of a reserved. Writing any
other value than the reset value may result in undefined behavior.
1232
AUX – Sensor Controller with Digital and Analog Peripherals SWCU117A–February 2015–Revised March 2015
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