wenkong_junshi/Examples/DAC/DAC_LFSR_noise_mode

/*!
\file readme.txt
\brief description of DAC_LFSR_noise_mode example

\version 2017-02-10, V1.0.0, firmware for GD32F30x
\version 2018-10-10, V1.1.0, firmware for GD32F30x
\version 2018-12-25, V2.0.0, firmware for GD32F30x
\version 2020-09-30, V2.1.0, firmware for GD32F30x
*/

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*/

This example is based on the GD32F307C-EVAL-V1.1 board, it shows how to use DAC to generate
LFSR noise wave.

TIMER5 is configured as following:
- Up counting mode.
- System clock devide into 1Mhz.
- Update event per millisecond.
- Update event as TRGO to trigger DAC.
DAC is configured as following:
- Data 12-bit right alligned.
- TIMER5 TRGO signal trigger DAC0_OUT0.
- DAC0_OUT0 is configured as PA4.
- LFSR mode, with 0-11 bit masking and offset value 0x7f0.

After system start-up, the LFSR noise wave can be observed through the oscilloscope.