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64 lines
1.3 KiB
64 lines
1.3 KiB
#include"usart.h"
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#include"pin.h"
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#define USART2_EN (1U << 17)
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#define CR1_TE_EN (1U << 3)
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#define CR1_UE_EN (1U << 0)
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#define ISR_TXE (1U << 7)
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#define UART_BAUD 115200
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#define SYST_CLK 8000000
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void usartSetBaudRate(uint32_t baud);
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void usartInit()
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{
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/* COnfiguring teh pins for the uart*/
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//pinConfig(pinA2, alternate, none, none, normal);
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//pinConfig(pinA15, alternate, none, none, normal);
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//Sets pina2 to alternate mode as UART_TX
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//pinSetAlternate(pinA2, 1);
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GPIOA->MODER &= ~(1u <<4);
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GPIOA->MODER |= (1u <<5);
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GPIOA->AFR[0] &= ~(1u<<11);
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GPIOA->AFR[0] &= ~(1u<<10);
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GPIOA->AFR[0] &= ~(1u<<9);
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GPIOA->AFR[0] |= (1u<<8);
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//Enable the priferas bus and UART
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RCC->APB1ENR |= USART2_EN;
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usartSetBaudRate(UART_BAUD);
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//enables the transmit and sets all the other values to 0 = Default
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USART2->CR1 = 0; // The = 0 is on purpose to set uart to default mode.
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USART2->CR1 |= CR1_TE_EN; // The = 0 is on purpose to set uart to default mode.
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//UART Enable
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USART2->CR1 |= CR1_UE_EN;
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}
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static uint16_t usartComputeBaudRate(uint32_t clk, uint32_t baud)
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{
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return((clk + (baud/2U))/baud);
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}
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void usartSetBaudRate(uint32_t baud)
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{
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USART2->BRR = usartComputeBaudRate(baud, SYST_CLK);
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}
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void usartSendChar(int ch)
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{
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// Make sure that TX buffer is empty
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while(!(USART2->ISR & ISR_TXE)){}
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USART2->TDR = (ch & 0xFF);
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}
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