diff options
| -rw-r--r-- | README.md | 5 | ||||
| -rw-r--r-- | usart/include/common.h | 12 | ||||
| -rw-r--r-- | usart/include/usart.h | 39 | ||||
| -rw-r--r-- | usart/src/main.c | 12 | ||||
| -rw-r--r-- | usart/src/usart.c | 34 |
5 files changed, 82 insertions, 20 deletions
@@ -23,3 +23,8 @@ Requirements * st-flash -- This can be found [here](https://github.com/texane/stlink.git) * perl * Cross compiler for arm -- Mine is installed with prefix `arm-unknown-eabi-`. + +Resources +--------- + +Datasheet may be found [here](http://www.st.com/content/ccc/resource/technical/document/reference_manual/group0/b0/ac/3e/8f/6d/21/47/af/DM00151940/files/DM00151940.pdf/jcr:content/translations/en.DM00151940.pdf) diff --git a/usart/include/common.h b/usart/include/common.h index d88d82d..9d5c7cd 100644 --- a/usart/include/common.h +++ b/usart/include/common.h @@ -1,6 +1,8 @@ #ifndef COMMON__H #define COMMON__H +#include <stdint.h> + /* Define __IO to be volatile if it's not already. */ #ifndef __IO #define __IO volatile @@ -15,4 +17,14 @@ #define PACKED __attribute__((packed)) #define BIT(n) (1 << (n)) +#define RESERVED_CONCAT_IMPL(x, y) x ## y +#define RESERVED_MACRO_CONCAT(x, y) RESERVED_CONCAT_IMPL(x, y) +#define RESERVED(n) \ + bits_t RESERVED_MACRO_CONCAT(_r, __COUNTER__) :n + +#define RESERVE(type) \ + __IO type RESERVED_MACRO_CONCAT(_r, __COUNTER__) + +typedef uint32_t bits_t; + #endif /* COMMON_H */ diff --git a/usart/include/usart.h b/usart/include/usart.h index ebc5458..257aab6 100644 --- a/usart/include/usart.h +++ b/usart/include/usart.h @@ -18,7 +18,33 @@ typedef enum { typedef struct { /* USART configuration registers 0x04 - 0x0c. */ - uint32_t c_r1; + union { + uint32_t c_r1; + struct { + bits_t ue:1; /* UART enable */ + bits_t uesm:1; /* UART enabled in stop mode. */ + bits_t re:1; /* reciever enabled. */ + bits_t te:1; /* transmitter enabled. */ + bits_t idleie:1; /* Idle interrupt enabled. */ + bits_t rxneie:1; /* RXNEIE RXNE interrupt enable. */ + bits_t tcie:1; + bits_t txeie:1; + bits_t peie:1; + bits_t ps:1; + bits_t pce:1; + bits_t wake:1; + bits_t m0:1; + bits_t mme:1; + bits_t cmie:1; + bits_t over8:1; + bits_t dedt:4; + bits_t deat:4; + bits_t rtoie:1; + bits_t eobie:1; + bits_t m1:1; + bits_t reserved:3; + } PACKED c1_bf; + }; uint32_t c_r2; uint32_t c_r3; @@ -73,10 +99,9 @@ typedef enum { } usart_parity_t; typedef enum { - USART_ENABLE_TX_RX = 0x0d, /* 0b1101 */ - USART_ENABLE_TX = 0x09, /* 0b1001 */ - USART_ENABLE_RX = 0x05, /* 0b0101 */ - USART_ENABLE_DISABLED = 0x00, /* 0b0000 */ + USART_ENABLE_TX = 0x02, + USART_ENABLE_RX = 0x01, + USART_ENABLE_DISABLED = 0x00, } usart_enable_t; void usart_set_parity(__IO usart_t* usart, usart_parity_t parity); @@ -97,6 +122,10 @@ void set_usart2_clock_src(__IO rcc_t* rcc, usart_clk_src_t usart_clk_src); void set_usart2_clock_enabled(__IO rcc_t* rcc, bool enable); +void usart_transmit_bytes( + __IO usart_t* usart, const uint8_t* bytes, uint32_t n); + +void usart_transmit_str(__IO usart_t* usart, const char* str); #endif /* H__USART_ */ diff --git a/usart/src/main.c b/usart/src/main.c index 5e33876..5af52ed 100644 --- a/usart/src/main.c +++ b/usart/src/main.c @@ -1,3 +1,4 @@ + #include "clock.h" #include "delay.h" #include "gpio.h" @@ -34,7 +35,7 @@ int enable_usart2(uint32_t baud_rate) USART2.c_r3 = 0; usart_set_divisor(&USART2, 16000000 / baud_rate); - usart_set_enabled(&USART2, USART_ENABLE_TX_RX); + usart_set_enabled(&USART2, USART_ENABLE_TX | USART_ENABLE_RX); } int enable_usart1(uint32_t baud_rate) @@ -82,12 +83,11 @@ int main() gpio_output_pin_t pin1 = set_gpio_pin_output(port_b, PIN_1); /* Enable a higher clock frequency. */ - // set_system_clock_MHz(80); + set_system_clock_MHz(80); - enable_usart2(9600); + enable_usart2(115200); pin_on(pin3); - while (true) { - usart_transmit_byte(&USART2, 0x32); - } + usart_transmit_str(&USART2, "Hello, World\n"); + for(;;); } diff --git a/usart/src/usart.c b/usart/src/usart.c index 23dbd95..eddfbe7 100644 --- a/usart/src/usart.c +++ b/usart/src/usart.c @@ -40,16 +40,15 @@ void usart_set_parity(__IO usart_t* usart, usart_parity_t parity) void usart_set_enabled(__IO usart_t* usart, usart_enable_t enabled) { uint32_t c_r1 = usart->c_r1; - /* Clear relevant bits. */ - c_r1 &= ~USART_ENABLE_TX_RX; - /* Set TX/RX enabled, but not actually USART enabled. */ - c_r1 |= (enabled & ~1); - - /* Set usart enabled bit separately. */ - c_r1 |= enabled & 1; - - usart->c_r1 = c_r1; + if (!enabled) { + usart->c1_bf.ue = 0; + } else { + /* Set the rx enabled. */ + usart->c1_bf.re = !!(enabled & USART_ENABLE_RX); + usart->c1_bf.te = !!(enabled & USART_ENABLE_TX); + usart->c1_bf.ue = 1; + } } void usart_transmit_byte(__IO usart_t* usart, uint8_t byte) @@ -62,3 +61,20 @@ void usart_transmit_byte(__IO usart_t* usart, uint8_t byte) while (!(usart->is_r & BIT(7))) ; } + +void usart_transmit_bytes(__IO usart_t* usart, const uint8_t* bytes, uint32_t n) +{ + while (n --) { + usart_transmit_byte(usart, *(bytes ++)); + } +} + +void usart_transmit_str(__IO usart_t* usart, const char* str) +{ + while (*str) { + if (*str == '\n') { + usart_transmit_byte(usart, '\r'); + } + usart_transmit_byte(usart, *(str ++)); + } +} |