Xmega Application Note | |||||
This file contains the function implementations for the XMEGA DAC 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 DAC 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.
Several 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.
Copyright (c) 2008, Atmel Corporation All rights reserved.
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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.
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Definition in file dac_driver.c.
#include "dac_driver.h"
Go to the source code of this file.
Functions | |
bool | DAC_Channel_DataEmpty (volatile DAC_t *dac, DAC_CH_t channel) |
Check if channel data register is empty. | |
void | DAC_Channel_Write (volatile DAC_t *dac, uint16_t data, DAC_CH_t channel) |
Write data to selected channel. | |
void | DAC_DualChannel_Enable (volatile DAC_t *dac, DAC_REFSEL_t convRef, bool leftAdjust, DAC_CONINTVAL_t sampleInterval, DAC_REFRESH_t refreshInterval) |
Enable Dual Channel. | |
void | DAC_EventAction_Set (volatile DAC_t *dac, DAC_TRIG_t trigChannel, uint8_t eventLine) |
Configure event actions. | |
void | DAC_SingleChannel_Enable (volatile DAC_t *dac, DAC_REFSEL_t convRef, bool leftAdjust) |
Enable Singe Channel. |
bool DAC_Channel_DataEmpty | ( | volatile DAC_t * | dac, | |
DAC_CH_t | channel | |||
) |
Check if channel data register is empty.
This function return the status of the data register empty flag for the selected channel in the given DAC module. This can be used to get the status of the register before writing a new value to it.
dac | Pointer to DAC module register section. | |
channel | Selected channel in the DAC module, either CH0 or CH1. |
dacStatus | True if data register is empty. | |
dacStatus | False if data register is not empty. |
Definition at line 153 of file dac_driver.c.
Referenced by main().
00154 { 00155 bool dacStatus = ( dac->STATUS & 00156 ( channel ? DAC_CH1DRE_bm : DAC_CH0DRE_bm )); 00157 return dacStatus; 00158 }
void DAC_Channel_Write | ( | volatile DAC_t * | dac, | |
uint16_t | data, | |||
DAC_CH_t | channel | |||
) |
Write data to selected channel.
This function writes data to the selected channel data register. The program should wait for the data register to be ready if necessary. This ensures that no intermediate values are lost with very high update rates.
dac | Pointer to DAC module register section. | |
data | Data to be converted. | |
channel | Selected channel in the DAC module, either CH0 or CH1. |
Definition at line 131 of file dac_driver.c.
References CH0.
Referenced by main().
00132 { 00133 if ( channel == CH0 ) { 00134 dac->CH0DATA = data; 00135 } else { 00136 dac->CH1DATA = data; 00137 } 00138 }
void DAC_DualChannel_Enable | ( | volatile DAC_t * | dac, | |
DAC_REFSEL_t | convRef, | |||
bool | leftAdjust, | |||
DAC_CONINTVAL_t | sampleInterval, | |||
DAC_REFRESH_t | refreshInterval | |||
) |
Enable Dual Channel.
This function configures the DAC to enable both channel outputs, in dual channel operation. It apply configuration parameters, save old values, clear affected bit field and set appropriate values.
dac | Pointer to DAC module register section. | |
convRef | Selects reference voltage for all conversions. | |
leftAdjust | Set to true to make data registers left adjusted. | |
sampleInterval | Interval between refreshing channel A and B. | |
refreshInterval | Interval between refresh cycles. |
Definition at line 103 of file dac_driver.c.
Referenced by main().
00108 { 00109 dac->CTRLB = ( dac->CTRLB & ~DAC_CHSEL_gm ) | DAC_CHSEL_DUAL_gc; 00110 dac->CTRLC = ( dac->CTRLC & ~( DAC_REFSEL_gm | DAC_LEFTADJ_bm ) ) | 00111 convRef | 00112 ( leftAdjust ? DAC_LEFTADJ_bm : 0x00 ); 00113 dac->TIMCTRL = (uint8_t) sampleInterval | refreshInterval; 00114 dac->CTRLA |= DAC_CH1EN_bm | DAC_CH0EN_bm | DAC_ENABLE_bm; 00115 }
void DAC_EventAction_Set | ( | volatile DAC_t * | dac, | |
DAC_TRIG_t | trigChannel, | |||
uint8_t | eventLine | |||
) |
Configure event actions.
This function configures the event action for the DAC module. It clears both control bits and set required bits.
dac | Pointer to DAC module register section. | |
trigChannel | The channels to be triggered by events. Values can be DAC_TRIG_0_0, DAC_TRIG_0_1, DAC_TRIG_1_0 or DAC_TRIG_0_0. | |
eventLine | Event line (0..7) to use for triggering conversions. |
Definition at line 174 of file dac_driver.c.
References DAC_TRIG_1_1.
00177 { 00178 dac->CTRLB = ( dac->CTRLB & ~DAC_TRIG_1_1 ) | trigChannel; 00179 dac->EVCTRL = eventLine & DAC_EVSEL_gm; 00180 }
void DAC_SingleChannel_Enable | ( | volatile DAC_t * | dac, | |
DAC_REFSEL_t | convRef, | |||
bool | leftAdjust | |||
) |
Enable Singe Channel.
This function configures the DAC to enable channel 0 output only, in single channel operation. It apply configuration parameters, save old values, clear affected bit field and set appropriate values.
dac | Pointer to DAC module register section. | |
convRef | Selects reference voltage for all conversions. | |
leftAdjust | Set to true to make data registers left adjusted. |
Definition at line 79 of file dac_driver.c.
00082 { 00083 dac->CTRLB = ( dac->CTRLB & ~DAC_CHSEL_gm ) | DAC_CHSEL_SINGLE_gc; 00084 dac->CTRLC = ( dac->CTRLC & ~(DAC_REFSEL_gm | DAC_LEFTADJ_bm) ) | 00085 convRef | ( leftAdjust ? DAC_LEFTADJ_bm : 0x00 ); 00086 dac->CTRLA = ( dac->CTRLA & ~DAC_CH1EN_bm ) | 00087 DAC_CH0EN_bm | DAC_ENABLE_bm; 00088 }
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