Datasheet

SD16SNGL = 1
Time
Conversion
SD16SC
SD16SNGL = 0
Conversion
SD16SC
Conversion Conversion
Set by SW
Auto−clear
Set by SW
Conv
Cleared by SW
= Result written to SD16MEM0
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26.2.9 Conversion Modes
The SD16_A module can be configured for two modes of operation, listed in Table 26-4. The SD16SNGL
bit selects the conversion mode.
Table 26-4. Conversion Mode Summary
SD16SNGL Mode Operation
1 Single conversion The channel is converted once.
0 Continuous conversion The channel is converted continuously.
26.2.9.1 Single Conversion
Setting the SD16SC bit of the channel initiates one conversion on that channel when SD16SNGL = 1. The
SD16SC bit will automatically be cleared after conversion completion.
Clearing SD16SC before the conversion is completed immediately stops conversion of the channel, the
channel is powered down and the corresponding digital filter is turned off. The value in SD16MEM0 can
change when SD16SC is cleared. It is recommended that the conversion data in SD16MEM0 be read
prior to clearing SD16SC to avoid reading an invalid result.
26.2.9.2 Continuous Conversion
When SD16SNGL = 0 continuous conversion mode is selected. Conversion of the channel will begin when
SD16SC is set and continue until the SD16SC bit is cleared by software.
Clearing SD16SC immediately stops conversion of the selected channel, the channel is powered down
and the corresponding digital filter is turned off. The value in SD16MEM0 can change when SD16SC is
cleared. It is recommended that the conversion data in SD16MEM0 be read prior to clearing SD16SC to
avoid reading an invalid result.
Figure 26-7 shows conversion operation.
Figure 26-7. Single Channel Operation
26.2.10 Using the Integrated Temperature Sensor
To use the on-chip temperature sensor, the user selects the analog input pair SD16INCHx = 110 and sets
SD16REFON = 1. Any other configuration is done as if an external analog input pair was selected,
including SD16INTDLYx and SD16GAINx settings. Because the internal reference must be on to use the
temperature sensor, it is not possible to use an external reference for the conversion of the temperature
sensor voltage. Also, the internal reference will be in contention with any used external reference. In this
case, the SD16VMIDON bit may be set to minimize the affects of the contention on the conversion.
The typical temperature sensor transfer function is shown in Figure 26-8. When switching inputs of an
SD16_A channel to the temperature sensor, adequate delay must be provided using SD16INTDLYx to
allow the digital filter to settle and assure that conversion results are valid. The temperature sensor offset
error can be large, and may need to be calibrated for most applications. See device-specific data sheet for
temperature sensor parameters.
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SD16_A SLAU144J–December 2004–Revised July 2013
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