mirror of
https://github.com/caperren/school_archives.git
synced 2025-11-09 13:41:13 +00:00
Corwin Perren
b300c76103
These are all design documents that I thought I had lost. It's may make me cringe, but it's still cool to use it to see how far I've come.
321 lines
10 KiB
C
321 lines
10 KiB
C
/* This file has been prepared for Doxygen automatic documentation generation.*/
|
|
/*! \file *********************************************************************
|
|
*
|
|
* \brief
|
|
* XMEGA USART driver source file.
|
|
*
|
|
* This file contains the function implementations the XMEGA interrupt
|
|
* and polled USART driver.
|
|
*
|
|
* The driver is not intended for size and/or speed critical code, since
|
|
* most functions are just a few lines of code, and the function call
|
|
* overhead would decrease code performance. The driver is intended for
|
|
* rapid prototyping and documentation purposes for getting started with
|
|
* the XMEGA ADC module.
|
|
*
|
|
* For size and/or speed critical code, it is recommended to copy the
|
|
* function contents directly into your application instead of making
|
|
* a function call.
|
|
*
|
|
* Some functions use the following construct:
|
|
* "some_register = ... | (some_parameter ? SOME_BIT_bm : 0) | ..."
|
|
* Although the use of the ternary operator ( if ? then : else ) is discouraged,
|
|
* in some occasions the operator makes it possible to write pretty clean and
|
|
* neat code. In this driver, the construct is used to set or not set a
|
|
* configuration bit based on a boolean input parameter, such as
|
|
* the "some_parameter" in the example above.
|
|
*
|
|
* \par Application note:
|
|
* AVR1307: Using the XMEGA USART
|
|
*
|
|
* \par Documentation
|
|
* For comprehensive code documentation, supported compilers, compiler
|
|
* settings and supported devices see readme.html
|
|
*
|
|
* \author
|
|
* Atmel Corporation: http://www.atmel.com \n
|
|
* Support email: avr@atmel.com
|
|
*
|
|
* $Revision: 1694 $
|
|
* $Date: 2008-07-29 14:21:58 +0200 (ti, 29 jul 2008) $ \n
|
|
*
|
|
* Copyright (c) 2008, Atmel Corporation All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright notice,
|
|
* this list of conditions and the following disclaimer.
|
|
*
|
|
* 2. Redistributions in binary form must reproduce the above copyright notice,
|
|
* this list of conditions and the following disclaimer in the documentation
|
|
* and/or other materials provided with the distribution.
|
|
*
|
|
* 3. The name of ATMEL may not be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
|
|
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY AND
|
|
* SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT,
|
|
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
|
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*****************************************************************************/
|
|
#include "usart_driver.h"
|
|
|
|
|
|
|
|
/*! \brief Initializes buffer and selects what USART module to use.
|
|
*
|
|
* Initializes receive and transmit buffer and selects what USART module to use,
|
|
* and stores the data register empty interrupt level.
|
|
*
|
|
* \param usart_data The USART_data_t struct instance.
|
|
* \param usart The USART module.
|
|
* \param dreIntLevel Data register empty interrupt level.
|
|
*/
|
|
void USART_InterruptDriver_Initialize(USART_data_t * usart_data,
|
|
USART_t * usart,
|
|
USART_DREINTLVL_t dreIntLevel)
|
|
{
|
|
usart_data->usart = usart;
|
|
usart_data->dreIntLevel = dreIntLevel;
|
|
|
|
usart_data->buffer.RX_Tail = 0;
|
|
usart_data->buffer.RX_Head = 0;
|
|
usart_data->buffer.TX_Tail = 0;
|
|
usart_data->buffer.TX_Head = 0;
|
|
}
|
|
|
|
|
|
/*! \brief Set USART DRE interrupt level.
|
|
*
|
|
* Set the interrupt level on Data Register interrupt.
|
|
*
|
|
* \note Changing the DRE interrupt level in the interrupt driver while it is
|
|
* running will not change the DRE interrupt level in the USART before the
|
|
* DRE interrupt have been disabled and enabled again.
|
|
*
|
|
* \param usart_data The USART_data_t struct instance
|
|
* \param dreIntLevel Interrupt level of the DRE interrupt.
|
|
*/
|
|
void USART_InterruptDriver_DreInterruptLevel_Set(USART_data_t * usart_data,
|
|
USART_DREINTLVL_t dreIntLevel)
|
|
{
|
|
usart_data->dreIntLevel = dreIntLevel;
|
|
}
|
|
|
|
|
|
/*! \brief Test if there is data in the transmitter software buffer.
|
|
*
|
|
* This function can be used to test if there is free space in the transmitter
|
|
* software buffer.
|
|
*
|
|
* \param usart_data The USART_data_t struct instance.
|
|
*
|
|
* \retval true There is data in the receive buffer.
|
|
* \retval false The receive buffer is empty.
|
|
*/
|
|
bool USART_TXBuffer_FreeSpace(USART_data_t * usart_data)
|
|
{
|
|
/* Make copies to make sure that volatile access is specified. */
|
|
uint8_t tempHead = (usart_data->buffer.TX_Head + 1) & USART_TX_BUFFER_MASK;
|
|
uint8_t tempTail = usart_data->buffer.TX_Tail;
|
|
|
|
/* There are data left in the buffer unless Head and Tail are equal. */
|
|
return (tempHead != tempTail);
|
|
}
|
|
|
|
|
|
|
|
/*! \brief Put data (5-8 bit character).
|
|
*
|
|
* Stores data byte in TX software buffer and enables DRE interrupt if there
|
|
* is free space in the TX software buffer.
|
|
*
|
|
* \param usart_data The USART_data_t struct instance.
|
|
* \param data The data to send.
|
|
*/
|
|
bool USART_TXBuffer_PutByte(USART_data_t * usart_data, uint8_t data)
|
|
{
|
|
uint8_t tempCTRLA;
|
|
uint8_t tempTX_Head;
|
|
bool TXBuffer_FreeSpace;
|
|
USART_Buffer_t * TXbufPtr;
|
|
|
|
TXbufPtr = &usart_data->buffer;
|
|
TXBuffer_FreeSpace = USART_TXBuffer_FreeSpace(usart_data);
|
|
|
|
|
|
if(TXBuffer_FreeSpace)
|
|
{
|
|
tempTX_Head = TXbufPtr->TX_Head;
|
|
TXbufPtr->TX[tempTX_Head]= data;
|
|
/* Advance buffer head. */
|
|
TXbufPtr->TX_Head = (tempTX_Head + 1) & USART_TX_BUFFER_MASK;
|
|
|
|
/* Enable DRE interrupt. */
|
|
tempCTRLA = usart_data->usart->CTRLA;
|
|
tempCTRLA = (tempCTRLA & ~USART_DREINTLVL_gm) | usart_data->dreIntLevel;
|
|
usart_data->usart->CTRLA = tempCTRLA;
|
|
}
|
|
return TXBuffer_FreeSpace;
|
|
}
|
|
|
|
|
|
|
|
/*! \brief Test if there is data in the receive software buffer.
|
|
*
|
|
* This function can be used to test if there is data in the receive software
|
|
* buffer.
|
|
*
|
|
* \param usart_data The USART_data_t struct instance
|
|
*
|
|
* \retval true There is data in the receive buffer.
|
|
* \retval false The receive buffer is empty.
|
|
*/
|
|
bool USART_RXBufferData_Available(USART_data_t * usart_data)
|
|
{
|
|
/* Make copies to make sure that volatile access is specified. */
|
|
uint8_t tempHead = usart_data->buffer.RX_Head;
|
|
uint8_t tempTail = usart_data->buffer.RX_Tail;
|
|
|
|
/* There are data left in the buffer unless Head and Tail are equal. */
|
|
return (tempHead != tempTail);
|
|
}
|
|
|
|
|
|
|
|
/*! \brief Get received data (5-8 bit character).
|
|
*
|
|
* The function USART_RXBufferData_Available should be used before this
|
|
* function is used to ensure that data is available.
|
|
*
|
|
* Returns data from RX software buffer.
|
|
*
|
|
* \param usart_data The USART_data_t struct instance.
|
|
*
|
|
* \return Received data.
|
|
*/
|
|
uint8_t USART_RXBuffer_GetByte(USART_data_t * usart_data)
|
|
{
|
|
USART_Buffer_t * bufPtr;
|
|
uint8_t ans;
|
|
|
|
bufPtr = &usart_data->buffer;
|
|
ans = (bufPtr->RX[bufPtr->RX_Tail]);
|
|
|
|
/* Advance buffer tail. */
|
|
bufPtr->RX_Tail = (bufPtr->RX_Tail + 1) & USART_RX_BUFFER_MASK;
|
|
|
|
return ans;
|
|
}
|
|
|
|
|
|
|
|
/*! \brief RX Complete Interrupt Service Routine.
|
|
*
|
|
* RX Complete Interrupt Service Routine.
|
|
* Stores received data in RX software buffer.
|
|
*
|
|
* \param usart_data The USART_data_t struct instance.
|
|
*/
|
|
bool USART_RXComplete(USART_data_t * usart_data)
|
|
{
|
|
USART_Buffer_t * bufPtr;
|
|
bool ans;
|
|
|
|
bufPtr = &usart_data->buffer;
|
|
/* Advance buffer head. */
|
|
uint8_t tempRX_Head = (bufPtr->RX_Head + 1) & USART_RX_BUFFER_MASK;
|
|
|
|
/* Check for overflow. */
|
|
uint8_t tempRX_Tail = bufPtr->RX_Tail;
|
|
uint8_t data = usart_data->usart->DATA;
|
|
|
|
if (tempRX_Head == tempRX_Tail) {
|
|
ans = false;
|
|
}else{
|
|
ans = true;
|
|
usart_data->buffer.RX[usart_data->buffer.RX_Head] = data;
|
|
usart_data->buffer.RX_Head = tempRX_Head;
|
|
}
|
|
return ans;
|
|
}
|
|
|
|
|
|
|
|
/*! \brief Data Register Empty Interrupt Service Routine.
|
|
*
|
|
* Data Register Empty Interrupt Service Routine.
|
|
* Transmits one byte from TX software buffer. Disables DRE interrupt if buffer
|
|
* is empty. Argument is pointer to USART (USART_data_t).
|
|
*
|
|
* \param usart_data The USART_data_t struct instance.
|
|
*/
|
|
void USART_DataRegEmpty(USART_data_t * usart_data)
|
|
{
|
|
USART_Buffer_t * bufPtr;
|
|
bufPtr = &usart_data->buffer;
|
|
|
|
/* Check if all data is transmitted. */
|
|
uint8_t tempTX_Tail = usart_data->buffer.TX_Tail;
|
|
if (bufPtr->TX_Head == tempTX_Tail){
|
|
/* Disable DRE interrupts. */
|
|
uint8_t tempCTRLA = usart_data->usart->CTRLA;
|
|
tempCTRLA = (tempCTRLA & ~USART_DREINTLVL_gm) | USART_DREINTLVL_OFF_gc;
|
|
usart_data->usart->CTRLA = tempCTRLA;
|
|
|
|
}else{
|
|
/* Start transmitting. */
|
|
uint8_t data = bufPtr->TX[usart_data->buffer.TX_Tail];
|
|
usart_data->usart->DATA = data;
|
|
|
|
/* Advance buffer tail. */
|
|
bufPtr->TX_Tail = (bufPtr->TX_Tail + 1) & USART_TX_BUFFER_MASK;
|
|
}
|
|
}
|
|
|
|
|
|
/*! \brief Put data (9 bit character).
|
|
*
|
|
* Use the function USART_IsTXDataRegisterEmpty before using this function to
|
|
* put 9 bit character to the TX register.
|
|
*
|
|
* \param usart The USART module.
|
|
* \param data The data to send.
|
|
*/
|
|
void USART_NineBits_PutChar(USART_t * usart, uint16_t data)
|
|
{
|
|
if(data & 0x0100) {
|
|
usart->CTRLB |= USART_TXB8_bm;
|
|
}else {
|
|
usart->CTRLB &= ~USART_TXB8_bm;
|
|
}
|
|
|
|
usart->DATA = (data & 0x00FF);
|
|
}
|
|
|
|
|
|
/*! \brief Get received data (9 bit character).
|
|
*
|
|
* This function reads out the received 9 bit character (uint16_t).
|
|
* Use the function USART_IsRXComplete to check if anything is received.
|
|
*
|
|
* \param usart The USART module.
|
|
*
|
|
* \retval Received data.
|
|
*/
|
|
uint16_t USART_NineBits_GetChar(USART_t * usart)
|
|
{
|
|
if(usart->CTRLB & USART_RXB8_bm) {
|
|
return(0x0100 | usart->DATA);
|
|
}else {
|
|
return(usart->DATA);
|
|
}
|
|
}
|