DocID025202 Rev 7
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RM0365
Analog-to-digital converters (ADC)
392
These thresholds are programmed in bits HT1[11:0] and LT1[11:0] of the ADCx_TR1
register for the analog watchdog 1. When converting data with a resolution of less than 12
bits (according to bits RES[1:0]), the LSB of the programmed thresholds must be kept
cleared because the internal comparison is always performed on the full 12-bit raw
converted data (left aligned).
describes how the comparison is performed for all the possible resolutions for
analog watchdog 1.
Description of analog watchdog 2 and 3
The second and third analog watchdogs are more flexible and can guard several selected
channels by programming the corresponding bits in AWDxCH[18:1] (x=2,3).
The corresponding watchdog is enabled when any bit of AWDxCH[18:0] (x=2,3) is set.
They are limited to a resolution of 8 bits and only the 8 MSBs of the thresholds can be
programmed into HTx[7:0] and LTx[7:0].
describes how the comparison is
performed for all the possible resolutions.
Table 92. Analog watchdog 1 comparison
Resolution
(bit
RES[1:0])
Analog watchdog comparison
between:
Comments
Raw converted
data, left aligned
(1)
1. The watchdog comparison is performed on the raw converted data before any alignment calculation and
before applying any offsets (the data which is compared is not signed).
Thresholds
00: 12-bit
DATA[11:0]
LT1[11:0] and
HT1[11:0]
-
01: 10-bit
DATA[11:2],00
LT1[11:0] and
HT1[11:0]
User must configure LT1[1:0] and HT1[1:0] to
00
10: 8-bit
DATA[11:4],0000
LT1[11:0] and
HT1[11:0]
User must configure LT1[3:0] and HT1[3:0] to
0000
11: 6-bit
DATA[11:6],000000
LT1[11:0] and
HT1[11:0]
User must configure LT1[5:0] and HT1[5:0] to
000000
Table 93. Analog watchdog 2 and 3 comparison
Resolution
(bits
RES[1:0])
Analog watchdog comparison between:
Comments
Raw converted data,
left aligned
(1)
Thresholds
00: 12-bit
DATA[11:4]
LTx[7:0] and
HTx[7:0]
DATA[3:0] are not relevant for the
comparison
01: 10-bit
DATA[11:4]
LTx[7:0] and
HTx[7:0]
DATA[3:2] are not relevant for the
comparison
10: 8-bit
DATA[11:4]
LTx[7:0] and
HTx[7:0]
-
11: 6-bit
DATA[11:6],00
LTx[7:0] and
HTx[7:0]
User must configure LTx[1:0] and
HTx[1:0] to 00