
Digital filter for sigma delta modulators (DFSDM)
RM0351
736/1830
DocID024597 Rev 5
Bit 17
RSWSTART
: Software start of a conversion on the regular channel
0: Writing ‘0’ has no effect
1: Writing ‘1’ makes a request to start a conversion on the regular channel and causes RCIP to
become ‘1’. If RCIP=1 already, writing to RSWSTART has no effect. Writing ‘1’ has no effect if
RSYNC=1.
This bit is always read as ‘0’.
Bits 16:15 Reserved, must be kept at reset value.
Bits 14:13
JEXTEN[1:0]
: Trigger enable and trigger edge selection for injected conversions
00: Trigger detection is disabled
01: Each rising edge on the selected trigger makes a request to launch an injected conversion
10: Each falling edge on the selected trigger makes a request to launch an injected conversion
11: Both rising edges and falling edges on the selected trigger make requests to launch injected
conversions
This bit can be modified only when DFEN=0 (DFSDM_FLTxCR1).
Bits 12:11 Reserved, must be kept at reset value.
Bits 10:8
JEXTSEL[2:0]
: Trigger signal selection for launching injected conversions
0x0-0x7: Trigger inputs selected by the following table.
This bit can be modified only when DFEN=0 (DFSDM_FLTxCR1).
DFSDM_FLT0
DFSDM_FLT1
DFSDM_FLT2
DFSDM_FLT3
0x00
dfsdm_jtrg0
dfsdm_jtrg0
dfsdm_jtrg0
dfsdm_jtrg0
0x01
dfsdm_jtrg1
dfsdm_jtrg1
dfsdm_jtrg1
dfsdm_jtrg1
0x02
dfsdm_jtrg2
dfsdm_jtrg2
dfsdm_jtrg2
dfsdm_jtrg2
0x03
dfsdm_jtrg3
dfsdm_jtrg3
dfsdm_jtrg3
dfsdm_jtrg4
0x04
dfsdm_jtrg5
dfsdm_jtrg5
dfsdm_jtrg5
dfsdm_jtrg6
0x05
dfsdm_jtrg7
dfsdm_jtrg7
dfsdm_jtrg8
dfsdm_jtrg8
0x06
dfsdm_jtrg9
dfsdm_jtrg9
dfsdm_jtrg9
dfsdm_jtrg9
0x07
dfsdm_jtrg10
dfsdm_jtrg10
dfsdm_jtrg10
dfsdm_jtrg10
Refer to
Table 154: DFSDM triggers connection
Bits 7:6 Reserved, must be kept at reset value.
Bit 5
JDMAEN
: DMA channel enabled to read data for the injected channel group
0: The DMA channel is not enabled to read injected data
1: The DMA channel is enabled to read injected data
This bit can be modified only when DFEN=0 (DFSDM_FLTxCR1).
Bit 4
JSCAN
: Scanning conversion mode for injected conversions
0: One channel conversion is performed from the injected channel group and next the selected
channel from this group is selected.
1: The series of conversions for the injected group channels is executed, starting over with the
lowest selected channel.
This bit can be modified only when DFEN=0 (DFSDM_FLTxCR1).
Writing JCHG if JSCAN=0 resets the channel selection to the lowest selected channel.
Bit 3
JSYNC
: Launch an injected conversion synchronously with the DFSDM_FLT0 JSWSTART trigger
0: Do not launch an injected conversion synchronously with DFSDM_FLT0
1: Launch an injected conversion in this DFSDM_FLTx at the very moment when an injected
conversion is launched in DFSDM_FLT0 by its JSWSTART trigger
This bit can be modified only when DFEN=0 (DFSDM_FLTxCR1).