RM0365 Datasheet, PDF (349/1076 Pages) STMicroelectronics – This reference manual targets application developers

Analog-to-digital converters (ADC)
RM0365
Note:
When using MDMA mode, the user must take care to configure properly the duration of the
master and slave conversions so that a DMA request is generated and served for reading
both data (master + slave) before a new conversion is available.
• MDMA=0b11: This mode is similar to the MDMA=0b10. The only differences are that
on each DMA request (two data items are available), two bytes representing two ADC
converted data items are transferred as a half-word.
This mode is used in interleaved and regular simultaneous mode when resolution is 6-
bit or when resolution is 8-bit and data is not signed (offsets must be disabled for all the
involved channels).
Example:
Interleaved dual mode: a DMA request is generated each time 2 data items are
available:
1st DMA request: ADCx_CDR[15:0] = SLV_ADCx_DR[7:0] | MST_ADCx_DR[7:0]
2nd DMA request: ADCx_CDR[15:0] = SLV_ADCx_DR[7:0] | MST_ADCx_DR[7:0]
Overrun detection
In dual ADC mode (when DUAL[4:0] is not equal to b00000), if an overrun is detected on
one of the ADCs, the DMA requests are no longer issued to ensure that all the data
transferred to the RAM are valid (this behavior occurs whatever the MDMA configuration). It
may happen that the EOC bit corresponding to one ADC remains set because the data
register of this ADC contains valid data.
DMA one shot mode/ DMA circular mode when MDMA mode is selected
When MDMA mode is selected (0b10 or 0b11), bit DMACFG of the ADCx_CCR register
must also be configured to select between DMA one shot mode and circular mode, as
explained in section Section : Managing conversions using the DMA (bits DMACFG of
master and slave ADCx_CFGR are not relevant).
Stopping the conversions in dual ADC modes
The user must set the control bits ADSTP/JADSTP of the master ADC to stop the
conversions of both ADC in dual ADC mode. The other ADSTP control bit of the slave ADC
has no effect in dual ADC mode.
Once both ADC are effectively stopped, the bits ADSTART/JADSTART of the master and
slave ADCs are both cleared by hardware.
15.3.30
Temperature sensor
The temperature sensor can be used to measure the junction temperature (TJ) of the
device. The temperature sensor is internally connected to the input channels which are
used to convert the sensor output voltage to a digital value. When not in use, the sensor can
be put in power down mode.
Figure 108 shows the block diagram of connections between the temperature sensor and
the ADC.
The temperature sensor output voltage changes linearly with temperature. The offset of this
line varies from chip to chip due to process variation (up to 45 °C from one chip to another).
The uncalibrated internal temperature sensor is more suited for applications that detect
temperature variations instead of absolute temperatures. To improve the accuracy of the
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