💡update comments

Author: csrohit

dma/include/main.h

@@ -1,12 +1,41 @@
 #ifndef __MAIN_H__
 
 #define __MAIN_H__
-
+/**
+ * @brief enable clock for dma1 peripheral registers
+ */
+void dma1_clock_enable(void);
+/**
+ * @brief Configure DMA1 channel 4 to work with USART1 transmitter
+ * It reads from memory and writes to USART data register
+ */
 void dma_usart_tx_init(void);
+
+/**
+ * @brief Configure DMA1 channel 4 to work with USART1 transmitter
+ * It reads from memory and writes to USART data register
+ */
 void dma_usart_rx_init(void);
+
+/**
+ * @brief Enable DMA to accept request for channel 4
+ */
 void dma_usart_tx_enable(void);
+
+/**
+ * @brief Enable DMA to accept request for channel 4
+ */
 void dma_usart_rx_enable(void);
+
+/**
+ * @brief Configure USART1 on PA9 and PA10
+ * Enable Transmitter with DMA
+ */
 void usart1_init(void);
+
+/**
+ * @brief Enable USART1 prescalers and output
+ */
 void usart1_enable(void);
 
 #endif

dma/src/main.c

@@ -22,25 +22,23 @@
 #define RX_BUFFER_LENGTH 20U
 #define TX_BUFFER_LENGTH 13U
 
-const char* msg = "Hello world\r\n\0";
+const char *msg = "Hello world\r\n\0";
 
 char buff[RX_BUFFER_LENGTH];
 
-
-/**
- * @brief Configure DMA1 channel 4 to work with USART1 transmitter
- * It reads from memory and writes to USART data register
- */
-void dma_usart_tx_init(void){
-	// enable clock for dma peripheral registers
+void dma1_clock_enable(void)
+{
 	RCC->AHBENR |= RCC_AHBENR_DMA1EN;
+}
 
+void dma_usart_tx_init(void)
+{
 	// USART TX is mapped to DMA1 channel 4
 	// set peripheral address to USART data register
-	DMA1_Channel4->CPAR = (uint32_t) &USART1->DR;
+	DMA1_Channel4->CPAR = (uint32_t)&USART1->DR;
 
 	// set memory address to address of string
-	DMA1_Channel4->CMAR = (uint32_t) msg;
+	DMA1_Channel4->CMAR = (uint32_t)msg;
 
 	// set number od dma transactions
 	DMA1_Channel4->CNDTR = RX_BUFFER_LENGTH;
@@ -55,56 +53,51 @@ void dma_usart_tx_init(void){
 	DMA1_Channel4->CCR |= DMA_CCR_DIR;
 }
 
-/**
- * @brief Enable DMA to accept request for channel 4
- */
-void dma_usart_tx_enable(void){
+void dma_usart_tx_enable(void)
+{
 	DMA1_Channel4->CCR |= DMA_CCR_EN;
 }
 
-void usart1_init(void){
+void usart1_init(void)
+{
 	// enable clock for GPIOA and USART1
-    RCC->APB2ENR |= RCC_APB2ENR_USART1EN | RCC_APB2ENR_IOPAEN;
+	RCC->APB2ENR |= RCC_APB2ENR_USART1EN | RCC_APB2ENR_IOPAEN;
 
-    // reset pin configurations for PA9 and PA10
-    GPIOA->CRH &= ~(GPIO_CRH_MODE10 | GPIO_CRH_MODE9 | GPIO_CRH_CNF10 | GPIO_CRH_CNF9);
+	// reset pin configurations for PA9 and PA10
+	GPIOA->CRH &= ~(GPIO_CRH_MODE10 | GPIO_CRH_MODE9 | GPIO_CRH_CNF10 | GPIO_CRH_CNF9);
 
-    // PA9 as Output@50Hz Alternate function
-    GPIOA->CRH |= GPIO_CRH_MODE9_0 | GPIO_CRH_MODE9_1 | GPIO_CRH_CNF9_1;
+	// PA9 as Output@50Hz Alternate function
+	GPIOA->CRH |= GPIO_CRH_MODE9_0 | GPIO_CRH_MODE9_1 | GPIO_CRH_CNF9_1;
 
-    // PA10 as floating input
-    GPIOA->CRH |= GPIO_CRH_CNF10_0;
+	// PA10 as floating input
+	GPIOA->CRH |= GPIO_CRH_CNF10_0;
 
 	// set baud rate as 9600
-    uint32_t baud = (uint32_t)(SystemCoreClock / 9600);
-    USART1->BRR = baud;
+	uint32_t baud = (uint32_t)(SystemCoreClock / 9600);
+	USART1->BRR = baud;
 
 	// Enable transmitter
 	USART1->CR1 |= USART_CR1_TE;
 
 	// Enable DMA mode for transmitter
-    USART1->CR3 |= USART_CR3_DMAT;
+	USART1->CR3 |= USART_CR3_DMAT;
 }
 
-/**
- * @brief Enable USART1 prescalers and output
- */
-void usart1_enable(void){
+void usart1_enable(void)
+{
 	USART1->CR1 |= USART_CR1_UE;
 }
 
 int main(void)
 {
-	SysTick_Config(SystemCoreClock/1000);
+	dma1_clock_enable();
+	SysTick_Config(SystemCoreClock / 1000);
 	usart1_init();
 	dma_usart_tx_init();
 	dma_usart_tx_enable();
 	usart1_enable();
 
 	while (1)
-	{	
-		
+	{
 	}
-	
-	
 }