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periph_conf.h File Reference

Configuration of CPU peripherals for the Atmel SAM D21 Xplained Pro board. More...

Detailed Description

Configuration of CPU peripherals for the Atmel SAM D21 Xplained Pro board.

Author
Travis Griggs travi.nosp@m.sgri.nosp@m.ggs@g.nosp@m.mail.nosp@m..com
Dan Evans photo.nosp@m.nthu.nosp@m.nder@.nosp@m.gmai.nosp@m.l.com

Definition in file periph_conf.h.

#include <stdint.h>
#include "cpu.h"
#include "periph_cpu.h"
+ Include dependency graph for periph_conf.h:
+ This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

External oscillator and clock configuration

There are three choices for selection of CORECLOCK:

  • usage of the 48 MHz DFLL fed by external oscillator running at 32 kHz
  • usage of the PLL fed by the internal 8MHz oscillator divided by 8
  • usage of the internal 8MHz oscillator directly, divided by N if needed

The PLL option allows for the usage of a wider frequency range and a more stable clock with less jitter. This is why this option is default.

The target frequency is computed from the PLL multiplier and the PLL divisor. Use the following formula to compute your values:

CORECLOCK = ((PLL_MUL + 1) * 1MHz) / PLL_DIV

NOTE: The PLL circuit does not run with less than 32MHz while the maximum PLL frequency is 96MHz. So PLL_MULL must be between 31 and 95!

The internal Oscillator used directly can lead to a slightly better power efficiency to the cost of a less stable clock. Use this option when you know what you are doing! The actual core frequency is adjusted as follows:

CORECLOCK = 8MHz / DIV

NOTE: A core clock frequency below 1MHz is not recommended

#define CLOCK_USE_PLL   (1)
 
#define CLOCK_USE_XOSC32_DFLL   (0)
 
#define GEN2_ULP32K   (0)
 
#define CLOCK_DIV   (1U)
 
#define CLOCK_CORECLOCK   (8000000 / CLOCK_DIV)
 

Timer peripheral configuration

#define TIMER_0_MAX_VALUE   0xffff
 
#define TIMER_0_ISR   isr_tc3
 
#define TIMER_1_ISR   isr_tc4
 
#define TIMER_NUMOF   ARRAY_SIZE(timer_config)
 
static const tc32_conf_t timer_config []
 

UART configuration

#define UART_0_ISR   isr_sercom3
 
#define UART_1_ISR   isr_sercom4
 
#define UART_2_ISR   isr_sercom5
 
#define UART_NUMOF   ARRAY_SIZE(uart_config)
 
static const uart_conf_t uart_config []
 

PWM configuration

#define PWM_0_EN   1
 
#define PWM_1_EN   0
 
#define PWM_2_EN   0
 
#define PWM_NUMOF   ARRAY_SIZE(pwm_config)
 
static const pwm_conf_t pwm_config []
 

SPI configuration

#define SPI_NUMOF   ARRAY_SIZE(spi_config)
 
static const spi_conf_t spi_config []
 

I2C configuration

#define I2C_NUMOF   ARRAY_SIZE(i2c_config)
 
static const i2c_conf_t i2c_config []
 

RTT configuration

#define RTT_FREQUENCY   (32768U) /* in Hz. For changes see `rtt.c` */
 

ADC Configuration

#define ADC_PRESCALER   ADC_CTRLB_PRESCALER_DIV512
 
#define ADC_NEG_INPUT   ADC_INPUTCTRL_MUXNEG_GND
 
#define ADC_GAIN_FACTOR_DEFAULT   ADC_INPUTCTRL_GAIN_1X
 
#define ADC_REF_DEFAULT   ADC_REFCTRL_REFSEL_INT1V
 
#define ADC_NUMOF   ARRAY_SIZE(adc_channels)
 
static const adc_conf_chan_t adc_channels []
 

DAC configuration

#define DAC_CLOCK   SAM0_GCLK_1MHZ
 
#define DAC_VREF   DAC_CTRLB_REFSEL_AVCC
 

USB peripheral configuration

static const sam0_common_usb_config_t sam_usbdev_config []
 

Macro Definition Documentation

◆ ADC_GAIN_FACTOR_DEFAULT

#define ADC_GAIN_FACTOR_DEFAULT   ADC_INPUTCTRL_GAIN_1X

Definition at line 352 of file periph_conf.h.

◆ ADC_NEG_INPUT

#define ADC_NEG_INPUT   ADC_INPUTCTRL_MUXNEG_GND

Definition at line 351 of file periph_conf.h.

◆ ADC_NUMOF

#define ADC_NUMOF   ARRAY_SIZE(adc_channels)

Definition at line 367 of file periph_conf.h.

◆ ADC_PRESCALER

#define ADC_PRESCALER   ADC_CTRLB_PRESCALER_DIV512

Definition at line 349 of file periph_conf.h.

◆ ADC_REF_DEFAULT

#define ADC_REF_DEFAULT   ADC_REFCTRL_REFSEL_INT1V

Definition at line 353 of file periph_conf.h.

◆ CLOCK_CORECLOCK

#define CLOCK_CORECLOCK   (8000000 / CLOCK_DIV)

Definition at line 92 of file periph_conf.h.

◆ CLOCK_DIV

#define CLOCK_DIV   (1U)

Definition at line 90 of file periph_conf.h.

◆ CLOCK_USE_PLL

#define CLOCK_USE_PLL   (1)

Definition at line 66 of file periph_conf.h.

◆ CLOCK_USE_XOSC32_DFLL

#define CLOCK_USE_XOSC32_DFLL   (0)

Definition at line 67 of file periph_conf.h.

◆ DAC_CLOCK

#define DAC_CLOCK   SAM0_GCLK_1MHZ

Definition at line 374 of file periph_conf.h.

◆ DAC_VREF

#define DAC_VREF   DAC_CTRLB_REFSEL_AVCC

Definition at line 376 of file periph_conf.h.

◆ GEN2_ULP32K

#define GEN2_ULP32K   (0)

Definition at line 75 of file periph_conf.h.

◆ I2C_NUMOF

#define I2C_NUMOF   ARRAY_SIZE(i2c_config)

Definition at line 331 of file periph_conf.h.

◆ PWM_0_EN

#define PWM_0_EN   1

Definition at line 197 of file periph_conf.h.

◆ PWM_1_EN

#define PWM_1_EN   0

Definition at line 198 of file periph_conf.h.

◆ PWM_2_EN

#define PWM_2_EN   0

Definition at line 199 of file periph_conf.h.

◆ PWM_NUMOF

#define PWM_NUMOF   ARRAY_SIZE(pwm_config)

Definition at line 255 of file periph_conf.h.

◆ RTT_FREQUENCY

#define RTT_FREQUENCY   (32768U) /* in Hz. For changes see `rtt.c` */

Definition at line 339 of file periph_conf.h.

◆ SPI_NUMOF

#define SPI_NUMOF   ARRAY_SIZE(spi_config)

Definition at line 313 of file periph_conf.h.

◆ TIMER_0_ISR

#define TIMER_0_ISR   isr_tc3

Definition at line 130 of file periph_conf.h.

◆ TIMER_0_MAX_VALUE

#define TIMER_0_MAX_VALUE   0xffff

Definition at line 127 of file periph_conf.h.

◆ TIMER_1_ISR

#define TIMER_1_ISR   isr_tc4

Definition at line 131 of file periph_conf.h.

◆ TIMER_NUMOF

#define TIMER_NUMOF   ARRAY_SIZE(timer_config)

Definition at line 133 of file periph_conf.h.

◆ UART_0_ISR

#define UART_0_ISR   isr_sercom3

Definition at line 186 of file periph_conf.h.

◆ UART_1_ISR

#define UART_1_ISR   isr_sercom4

Definition at line 187 of file periph_conf.h.

◆ UART_2_ISR

#define UART_2_ISR   isr_sercom5

Definition at line 188 of file periph_conf.h.

◆ UART_NUMOF

#define UART_NUMOF   ARRAY_SIZE(uart_config)

Definition at line 190 of file periph_conf.h.

Variable Documentation

◆ adc_channels

const adc_conf_chan_t adc_channels[]
static
Initial value:
= {
{ .inputctrl = ADC_INPUTCTRL_MUXPOS_PB00 },
{ .inputctrl = ADC_INPUTCTRL_MUXPOS_PB01 },
{ .inputctrl = ADC_INPUTCTRL_MUXPOS_PA10 },
{ .inputctrl = ADC_INPUTCTRL_MUXPOS_PA11 },
{ .inputctrl = ADC_INPUTCTRL_MUXPOS_PA02 },
{ .inputctrl = ADC_INPUTCTRL_MUXPOS_PA03 }
}
#define ADC_INPUTCTRL_MUXPOS_PA10
Alias for PIN18.
Definition periph_cpu.h:137
#define ADC_INPUTCTRL_MUXPOS_PA11
Alias for PIN19.
Definition periph_cpu.h:138
#define ADC_INPUTCTRL_MUXPOS_PB01
Alias for PIN9.
Definition periph_cpu.h:128
#define ADC_INPUTCTRL_MUXPOS_PA02
ADC pin aliases.
Definition periph_cpu.h:119
#define ADC_INPUTCTRL_MUXPOS_PA03
Alias for PIN1.
Definition periph_cpu.h:120
#define ADC_INPUTCTRL_MUXPOS_PB00
Alias for PIN8.
Definition periph_cpu.h:127

Definition at line 355 of file periph_conf.h.

◆ i2c_config

const i2c_conf_t i2c_config[]
static
Initial value:
= {
{
.dev = &(SERCOM2->I2CM),
.speed = I2C_SPEED_NORMAL,
.scl_pin = GPIO_PIN(PA, 9),
.sda_pin = GPIO_PIN(PA, 8),
.mux = GPIO_MUX_D,
.gclk_src = SAM0_GCLK_MAIN,
.flags = I2C_FLAG_NONE
}
}
#define GPIO_PIN(x, y)
Define a CPU specific GPIO pin generator macro.
Definition periph_cpu.h:46
@ I2C_SPEED_NORMAL
normal mode: ~100 kbit/s
Definition periph_cpu.h:278
@ PA
port A
@ I2C_FLAG_NONE
No flags set.
@ GPIO_MUX_D
select peripheral function D
#define SAM0_GCLK_MAIN
120 MHz main clock
Definition periph_cpu.h:74

Definition at line 320 of file periph_conf.h.

◆ pwm_config

const pwm_conf_t pwm_config[]
static
Initial value:
= {
}

Definition at line 227 of file periph_conf.h.

◆ sam_usbdev_config

const sam0_common_usb_config_t sam_usbdev_config[]
static
Initial value:
= {
{
.dm = GPIO_PIN(PA, 24),
.dp = GPIO_PIN(PA, 25),
.d_mux = GPIO_MUX_G,
.device = &USB->DEVICE,
.gclk_src = SAM0_GCLK_MAIN,
}
}
@ GPIO_MUX_G
select peripheral function G

Definition at line 383 of file periph_conf.h.

◆ spi_config

const spi_conf_t spi_config[]
static

Definition at line 262 of file periph_conf.h.

◆ timer_config

const tc32_conf_t timer_config[]
static
Initial value:
= {
{
.dev = TC3,
.irq = TC3_IRQn,
.pm_mask = PM_APBCMASK_TC3,
.gclk_ctrl = GCLK_CLKCTRL_ID_TCC2_TC3,
.gclk_src = SAM0_GCLK_MAIN,
.flags = TC_CTRLA_MODE_COUNT16,
},
{
.dev = TC4,
.irq = TC4_IRQn,
.pm_mask = PM_APBCMASK_TC4 | PM_APBCMASK_TC5,
.gclk_ctrl = GCLK_CLKCTRL_ID_TC4_TC5,
.gclk_src = SAM0_GCLK_MAIN,
.flags = TC_CTRLA_MODE_COUNT32,
}
}

Definition at line 100 of file periph_conf.h.

◆ uart_config

const uart_conf_t uart_config[]
static

Definition at line 140 of file periph_conf.h.