Information

Description STM32F405xx, STM32F407xx
38/185 DocID022152 Rev 4
connected to the ADC1_IN16 input channel which is used to convert the sensor output
voltage into a digital value.
As the offset of the temperature sensor varies from chip to chip due to process variation, the
internal temperature sensor is mainly suitable for applications that detect temperature
changes instead of absolute temperatures. If an accurate temperature reading is needed,
then an external temperature sensor part should be used.
2.2.37 Digital-to-analog converter (DAC)
The two 12-bit buffered DAC channels can be used to convert two digital signals into two
analog voltage signal outputs.
This dual digital Interface supports the following features:
• two DAC converters: one for each output channel
• 8-bit or 12-bit monotonic output
• left or right data alignment in 12-bit mode
• synchronized update capability
• noise-wave generation
• triangular-wave generation
• dual DAC channel independent or simultaneous conversions
• DMA capability for each channel
• external triggers for conversion
• input voltage reference V
REF+
Eight DAC trigger inputs are used in the device. The DAC channels are triggered through
the timer update outputs that are also connected to different DMA streams.
2.2.38 Serial wire JTAG debug port (SWJ-DP)
The ARM SWJ-DP interface is embedded, and is a combined JTAG and serial wire debug
port that enables either a serial wire debug or a JTAG probe to be connected to the target.
Debug is performed using 2 pins only instead of 5 required by the JTAG (JTAG pins could
be re-use as GPIO with alternate function): the JTAG TMS and TCK pins are shared with
SWDIO and SWCLK, respectively, and a specific sequence on the TMS pin is used to
switch between JTAG-DP and SW-DP.
2.2.39 Embedded Trace Macrocell™
The ARM Embedded Trace Macrocell provides a greater visibility of the instruction and data
flow inside the CPU core by streaming compressed data at a very high rate from the
STM32F40x through a small number of ETM pins to an external hardware trace port
analyser (TPA) device. The TPA is connected to a host computer using USB, Ethernet, or
any other high-speed channel. Real-time instruction and data flow activity can be recorded
and then formatted for display on the host computer that runs the debugger software. TPA
hardware is commercially available from common development tool vendors.
The Embedded Trace Macrocell operates with third party debugger software tools.