00. Table of Contents
Article Directory
01. Introduction to DAC
The DAC module (digital/analog conversion module) of STM32F4 is a 12-bit digital input, voltage output type DAC. The DAC can be configured in 8-bit or 12-bit mode, and it can also be used with a DMA controller. When the DAC works in 12-bit mode, the data can be set to left-justified or right-justified. The DAC module has 2 output channels, and each channel has a separate converter. In dual DAC mode, two channels can be converted independently, or they can be converted simultaneously and update the output of the two channels simultaneously. DAC can input reference voltage Vref+ (shared by ADC) through the pin to obtain more accurate conversion results.
The main features of STM32F4's DAC module are:
① 2 DAC converters: each converter corresponds to one output channel
② 8-bit or 12-bit monotonic output
③ Left-aligned or right-aligned data in 12-bit mode
④ Synchronous update function
⑤ Noise waveform Generate
⑥ Triangular waveform generation
⑦ Dual DAC channels can be converted simultaneously or separately
⑧ Each channel has DMA function
02. Related types
DAC Init structure
/**
* @brief DAC Init structure definition
*/
typedef struct
{
uint32_t DAC_Trigger; /*!< Specifies the external trigger for the selected DAC channel.
This parameter can be a value of @ref DAC_trigger_selection */
uint32_t DAC_WaveGeneration; /*!< Specifies whether DAC channel noise waves or triangle waves
are generated, or whether no wave is generated.
This parameter can be a value of @ref DAC_wave_generation */
uint32_t DAC_LFSRUnmask_TriangleAmplitude; /*!< Specifies the LFSR mask for noise wave generation or
the maximum amplitude triangle generation for the DAC channel.
This parameter can be a value of @ref DAC_lfsrunmask_triangleamplitude */
uint32_t DAC_OutputBuffer; /*!< Specifies whether the DAC channel output buffer is enabled or disabled.
This parameter can be a value of @ref DAC_output_buffer */
}DAC_InitTypeDef;
DAC_trigger_selection
/** @defgroup DAC_trigger_selection
* @{
*/
#define DAC_Trigger_None ((uint32_t)0x00000000) /*!< Conversion is automatic once the DAC1_DHRxxxx register
has been loaded, and not by external trigger */
#define DAC_Trigger_T2_TRGO ((uint32_t)0x00000024) /*!< TIM2 TRGO selected as external conversion trigger for DAC channel */
#define DAC_Trigger_T4_TRGO ((uint32_t)0x0000002C) /*!< TIM4 TRGO selected as external conversion trigger for DAC channel */
#define DAC_Trigger_T5_TRGO ((uint32_t)0x0000001C) /*!< TIM5 TRGO selected as external conversion trigger for DAC channel */
#define DAC_Trigger_T6_TRGO ((uint32_t)0x00000004) /*!< TIM6 TRGO selected as external conversion trigger for DAC channel */
#define DAC_Trigger_T7_TRGO ((uint32_t)0x00000014) /*!< TIM7 TRGO selected as external conversion trigger for DAC channel */
#define DAC_Trigger_T8_TRGO ((uint32_t)0x0000000C) /*!< TIM8 TRGO selected as external conversion trigger for DAC channel */
#define DAC_Trigger_Ext_IT9 ((uint32_t)0x00000034) /*!< EXTI Line9 event selected as external conversion trigger for DAC channel */
#define DAC_Trigger_Software ((uint32_t)0x0000003C) /*!< Conversion started by software trigger for DAC channel */
#define IS_DAC_TRIGGER(TRIGGER) (((TRIGGER) == DAC_Trigger_None) || \
((TRIGGER) == DAC_Trigger_T6_TRGO) || \
((TRIGGER) == DAC_Trigger_T8_TRGO) || \
((TRIGGER) == DAC_Trigger_T7_TRGO) || \
((TRIGGER) == DAC_Trigger_T5_TRGO) || \
((TRIGGER) == DAC_Trigger_T2_TRGO) || \
((TRIGGER) == DAC_Trigger_T4_TRGO) || \
((TRIGGER) == DAC_Trigger_Ext_IT9) || \
((TRIGGER) == DAC_Trigger_Software))
DAC_wave_generation
/** @defgroup DAC_wave_generation
* @{
*/
#define DAC_WaveGeneration_None ((uint32_t)0x00000000)
#define DAC_WaveGeneration_Noise ((uint32_t)0x00000040)
#define DAC_WaveGeneration_Triangle ((uint32_t)0x00000080)
#define IS_DAC_GENERATE_WAVE(WAVE) (((WAVE) == DAC_WaveGeneration_None) || \
((WAVE) == DAC_WaveGeneration_Noise) || \
((WAVE) == DAC_WaveGeneration_Triangle))
DAC_lfsrunmask_triangleamplitude
/** @defgroup DAC_lfsrunmask_triangleamplitude
* @{
*/
#define DAC_LFSRUnmask_Bit0 ((uint32_t)0x00000000) /*!< Unmask DAC channel LFSR bit0 for noise wave generation */
#define DAC_LFSRUnmask_Bits1_0 ((uint32_t)0x00000100) /*!< Unmask DAC channel LFSR bit[1:0] for noise wave generation */
#define DAC_LFSRUnmask_Bits2_0 ((uint32_t)0x00000200) /*!< Unmask DAC channel LFSR bit[2:0] for noise wave generation */
#define DAC_LFSRUnmask_Bits3_0 ((uint32_t)0x00000300) /*!< Unmask DAC channel LFSR bit[3:0] for noise wave generation */
#define DAC_LFSRUnmask_Bits4_0 ((uint32_t)0x00000400) /*!< Unmask DAC channel LFSR bit[4:0] for noise wave generation */
#define DAC_LFSRUnmask_Bits5_0 ((uint32_t)0x00000500) /*!< Unmask DAC channel LFSR bit[5:0] for noise wave generation */
#define DAC_LFSRUnmask_Bits6_0 ((uint32_t)0x00000600) /*!< Unmask DAC channel LFSR bit[6:0] for noise wave generation */
#define DAC_LFSRUnmask_Bits7_0 ((uint32_t)0x00000700) /*!< Unmask DAC channel LFSR bit[7:0] for noise wave generation */
#define DAC_LFSRUnmask_Bits8_0 ((uint32_t)0x00000800) /*!< Unmask DAC channel LFSR bit[8:0] for noise wave generation */
#define DAC_LFSRUnmask_Bits9_0 ((uint32_t)0x00000900) /*!< Unmask DAC channel LFSR bit[9:0] for noise wave generation */
#define DAC_LFSRUnmask_Bits10_0 ((uint32_t)0x00000A00) /*!< Unmask DAC channel LFSR bit[10:0] for noise wave generation */
#define DAC_LFSRUnmask_Bits11_0 ((uint32_t)0x00000B00) /*!< Unmask DAC channel LFSR bit[11:0] for noise wave generation */
#define DAC_TriangleAmplitude_1 ((uint32_t)0x00000000) /*!< Select max triangle amplitude of 1 */
#define DAC_TriangleAmplitude_3 ((uint32_t)0x00000100) /*!< Select max triangle amplitude of 3 */
#define DAC_TriangleAmplitude_7 ((uint32_t)0x00000200) /*!< Select max triangle amplitude of 7 */
#define DAC_TriangleAmplitude_15 ((uint32_t)0x00000300) /*!< Select max triangle amplitude of 15 */
#define DAC_TriangleAmplitude_31 ((uint32_t)0x00000400) /*!< Select max triangle amplitude of 31 */
#define DAC_TriangleAmplitude_63 ((uint32_t)0x00000500) /*!< Select max triangle amplitude of 63 */
#define DAC_TriangleAmplitude_127 ((uint32_t)0x00000600) /*!< Select max triangle amplitude of 127 */
#define DAC_TriangleAmplitude_255 ((uint32_t)0x00000700) /*!< Select max triangle amplitude of 255 */
#define DAC_TriangleAmplitude_511 ((uint32_t)0x00000800) /*!< Select max triangle amplitude of 511 */
#define DAC_TriangleAmplitude_1023 ((uint32_t)0x00000900) /*!< Select max triangle amplitude of 1023 */
#define DAC_TriangleAmplitude_2047 ((uint32_t)0x00000A00) /*!< Select max triangle amplitude of 2047 */
#define DAC_TriangleAmplitude_4095 ((uint32_t)0x00000B00) /*!< Select max triangle amplitude of 4095 */
#define IS_DAC_LFSR_UNMASK_TRIANGLE_AMPLITUDE(VALUE) (((VALUE) == DAC_LFSRUnmask_Bit0) || \
((VALUE) == DAC_LFSRUnmask_Bits1_0) || \
((VALUE) == DAC_LFSRUnmask_Bits2_0) || \
((VALUE) == DAC_LFSRUnmask_Bits3_0) || \
((VALUE) == DAC_LFSRUnmask_Bits4_0) || \
((VALUE) == DAC_LFSRUnmask_Bits5_0) || \
((VALUE) == DAC_LFSRUnmask_Bits6_0) || \
((VALUE) == DAC_LFSRUnmask_Bits7_0) || \
((VALUE) == DAC_LFSRUnmask_Bits8_0) || \
((VALUE) == DAC_LFSRUnmask_Bits9_0) || \
((VALUE) == DAC_LFSRUnmask_Bits10_0) || \
((VALUE) == DAC_LFSRUnmask_Bits11_0) || \
((VALUE) == DAC_TriangleAmplitude_1) || \
((VALUE) == DAC_TriangleAmplitude_3) || \
((VALUE) == DAC_TriangleAmplitude_7) || \
((VALUE) == DAC_TriangleAmplitude_15) || \
((VALUE) == DAC_TriangleAmplitude_31) || \
((VALUE) == DAC_TriangleAmplitude_63) || \
((VALUE) == DAC_TriangleAmplitude_127) || \
((VALUE) == DAC_TriangleAmplitude_255) || \
((VALUE) == DAC_TriangleAmplitude_511) || \
((VALUE) == DAC_TriangleAmplitude_1023) || \
((VALUE) == DAC_TriangleAmplitude_2047) || \
((VALUE) == DAC_TriangleAmplitude_4095))
DAC_output_buffer
/** @defgroup DAC_output_buffer
* @{
*/
#define DAC_OutputBuffer_Enable ((uint32_t)0x00000000)
#define DAC_OutputBuffer_Disable ((uint32_t)0x00000002)
#define IS_DAC_OUTPUT_BUFFER_STATE(STATE) (((STATE) == DAC_OutputBuffer_Enable) || \
((STATE) == DAC_OutputBuffer_Disable))
DAC_Channel_selection
/** @defgroup DAC_Channel_selection
* @{
*/
#define DAC_Channel_1 ((uint32_t)0x00000000)
#define DAC_Channel_2 ((uint32_t)0x00000010)
#define IS_DAC_CHANNEL(CHANNEL) (((CHANNEL) == DAC_Channel_1) || \
((CHANNEL) == DAC_Channel_2))
DAC_data_alignment
/** @defgroup DAC_data_alignement
* @{
*/
#define DAC_Align_12b_R ((uint32_t)0x00000000)
#define DAC_Align_12b_L ((uint32_t)0x00000004)
#define DAC_Align_8b_R ((uint32_t)0x00000008)
#define IS_DAC_ALIGN(ALIGN) (((ALIGN) == DAC_Align_12b_R) || \
((ALIGN) == DAC_Align_12b_L) || \
((ALIGN) == DAC_Align_8b_R))
DAC_wave_generation
/** @defgroup DAC_wave_generation
* @{
*/
#define DAC_Wave_Noise ((uint32_t)0x00000040)
#define DAC_Wave_Triangle ((uint32_t)0x00000080)
#define IS_DAC_WAVE(WAVE) (((WAVE) == DAC_Wave_Noise) || \
((WAVE) == DAC_Wave_Triangle))
other
/** @defgroup DAC_data
* @{
*/
#define IS_DAC_DATA(DATA) ((DATA) <= 0xFFF0)
/**
* @}
*/
/** @defgroup DAC_interrupts_definition
* @{
*/
#define DAC_IT_DMAUDR ((uint32_t)0x00002000)
#define IS_DAC_IT(IT) (((IT) == DAC_IT_DMAUDR))
/**
* @}
*/
/** @defgroup DAC_flags_definition
* @{
*/
#define DAC_FLAG_DMAUDR ((uint32_t)0x00002000)
#define IS_DAC_FLAG(FLAG) (((FLAG) == DAC_FLAG_DMAUDR))
03. Related functions
/* Function used to set the DAC configuration to the default reset state *****/
void DAC_DeInit(void);
/* DAC channels configuration: trigger, output buffer, data format functions */
void DAC_Init(uint32_t DAC_Channel, DAC_InitTypeDef* DAC_InitStruct);
void DAC_StructInit(DAC_InitTypeDef* DAC_InitStruct);
void DAC_Cmd(uint32_t DAC_Channel, FunctionalState NewState);
void DAC_SoftwareTriggerCmd(uint32_t DAC_Channel, FunctionalState NewState);
void DAC_DualSoftwareTriggerCmd(FunctionalState NewState);
void DAC_WaveGenerationCmd(uint32_t DAC_Channel, uint32_t DAC_Wave, FunctionalState NewState);
void DAC_SetChannel1Data(uint32_t DAC_Align, uint16_t Data);
void DAC_SetChannel2Data(uint32_t DAC_Align, uint16_t Data);
void DAC_SetDualChannelData(uint32_t DAC_Align, uint16_t Data2, uint16_t Data1);
uint16_t DAC_GetDataOutputValue(uint32_t DAC_Channel);
/* DMA management functions ***************************************************/
void DAC_DMACmd(uint32_t DAC_Channel, FunctionalState NewState);
/* Interrupts and flags management functions **********************************/
void DAC_ITConfig(uint32_t DAC_Channel, uint32_t DAC_IT, FunctionalState NewState);
FlagStatus DAC_GetFlagStatus(uint32_t DAC_Channel, uint32_t DAC_FLAG);
void DAC_ClearFlag(uint32_t DAC_Channel, uint32_t DAC_FLAG);
ITStatus DAC_GetITStatus(uint32_t DAC_Channel, uint32_t DAC_IT);
void DAC_ClearITPendingBit(uint32_t DAC_Channel, uint32_t DAC_IT);
04. Structure package
/**
* @brief Digital to Analog Converter
*/
typedef struct
{
__IO uint32_t CR; /*!< DAC control register, Address offset: 0x00 */
__IO uint32_t SWTRIGR; /*!< DAC software trigger register, Address offset: 0x04 */
__IO uint32_t DHR12R1; /*!< DAC channel1 12-bit right-aligned data holding register, Address offset: 0x08 */
__IO uint32_t DHR12L1; /*!< DAC channel1 12-bit left aligned data holding register, Address offset: 0x0C */
__IO uint32_t DHR8R1; /*!< DAC channel1 8-bit right aligned data holding register, Address offset: 0x10 */
__IO uint32_t DHR12R2; /*!< DAC channel2 12-bit right aligned data holding register, Address offset: 0x14 */
__IO uint32_t DHR12L2; /*!< DAC channel2 12-bit left aligned data holding register, Address offset: 0x18 */
__IO uint32_t DHR8R2; /*!< DAC channel2 8-bit right-aligned data holding register, Address offset: 0x1C */
__IO uint32_t DHR12RD; /*!< Dual DAC 12-bit right-aligned data holding register, Address offset: 0x20 */
__IO uint32_t DHR12LD; /*!< DUAL DAC 12-bit left aligned data holding register, Address offset: 0x24 */
__IO uint32_t DHR8RD; /*!< DUAL DAC 8-bit right aligned data holding register, Address offset: 0x28 */
__IO uint32_t DOR1; /*!< DAC channel1 data output register, Address offset: 0x2C */
__IO uint32_t DOR2; /*!< DAC channel2 data output register, Address offset: 0x30 */
__IO uint32_t SR; /*!< DAC status register, Address offset: 0x34 */
} DAC_TypeDef;
05. Reserved
06. Appendix
6.1 [STM32] STM32 series tutorial summary
Website: [STM32] STM32 series tutorial summary
07. Statement
STM32F4xx English Reference Manual