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Use safe clock freqs for AnalogOut; use DAC REFRESH on SAMD51. #649

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Merged
merged 2 commits into from
Feb 27, 2018
Merged

Use safe clock freqs for AnalogOut; use DAC REFRESH on SAMD51. #649

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4895a9d
Use safe clock freqs for AnalogOut; use DAC REFRESH on SAMD51.
dhalbert Feb 27, 2018
5c24023
use CONF_GCLK_DAC_SRC and refactor a bit
dhalbert Feb 27, 2018
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11 changes: 6 additions & 5 deletions ports/atmel-samd/asf4_conf/samd21/hpl_gclk_config.h
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@@ -1,12 +1,13 @@
// Circuit Python SAMD21 clock tree:
// DFLL48M (with USBCRM on to sync with external USB ref) -> GCLK0
// DFLL48M (with USBCRM on to sync with external USB ref) -> GCLK0, GCLK1
// GCLK0 (48MHz) -> peripherals
// GLCK1 (48MHz divided by 150 = 320Khz) -> DAC peripheral (DAC requires 350KHz or lower)

// We'd like to use XOSC32K as a ref for DFLL48M on boards with a 32kHz crystal,
// but haven't figured that out yet.

// Used in hpl/core/hpl_init.c to define which clocks should be initialized first.
#define CIRCUITPY_GCLK_INIT_1ST (1 << 0)
#define CIRCUITPY_GCLK_INIT_1ST (1 << 0 | 1 << 1)


/* Auto-generated config file hpl_gclk_config.h */
Expand Down Expand Up @@ -127,7 +128,7 @@
// <i> Indicates whether Output Enable is enabled or not
// <id> gclk_arch_gen_1_oe
#ifndef CONF_GCLK_GEN_1_OE
#define CONF_GCLK_GEN_1_OE 0
#define CONF_GCLK_GEN_1_OE 1
#endif

// <q> Output Off Value
Expand Down Expand Up @@ -172,7 +173,7 @@
// <i> This defines the clock source for generic clock generator 1
// <id> gclk_gen_1_oscillator
#ifndef CONF_GCLK_GEN_1_SRC
#define CONF_GCLK_GEN_1_SRC GCLK_GENCTRL_SRC_XOSC32K
#define CONF_GCLK_GEN_1_SRC GCLK_GENCTRL_SRC_DFLL48M
#endif
// </h>

Expand All @@ -181,7 +182,7 @@
// <i>
// <id> gclk_gen_1_div
#ifndef CONF_GCLK_GEN_1_DIV
#define CONF_GCLK_GEN_1_DIV 1
#define CONF_GCLK_GEN_1_DIV 150
#endif

// </h>
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4 changes: 2 additions & 2 deletions ports/atmel-samd/asf4_conf/samd21/peripheral_clk_config.h
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Expand Up @@ -385,15 +385,15 @@

// <i> Select the clock source for DAC.
#ifndef CONF_GCLK_DAC_SRC
#define CONF_GCLK_DAC_SRC GCLK_CLKCTRL_GEN_GCLK0_Val
#define CONF_GCLK_DAC_SRC GCLK_CLKCTRL_GEN_GCLK1_Val
#endif

/**
* \def CONF_GCLK_DAC_FREQUENCY
* \brief DAC's Clock frequency
*/
#ifndef CONF_GCLK_DAC_FREQUENCY
#define CONF_GCLK_DAC_FREQUENCY 48000000
#define CONF_GCLK_DAC_FREQUENCY 320000
#endif

// <y> USB Clock Source
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4 changes: 2 additions & 2 deletions ports/atmel-samd/asf4_conf/samd51/hpl_dac_config.h
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Expand Up @@ -72,7 +72,7 @@
// <i> This defines the refresh period. If it is 0, the refresh mode is disabled, else the refresh period is: value * 500us
// <id> dac0_arch_refresh
#ifndef CONF_DAC0_REFRESH
#define CONF_DAC0_REFRESH 0
#define CONF_DAC0_REFRESH 2
#endif
// </h>
// <h> Channel 1 configuration
Expand Down Expand Up @@ -111,7 +111,7 @@
// <i> This defines the refresh period. If it is 0, the refresh mode is disabled, else the refresh period is: value * 500us
// <id> dac1_arch_refresh
#ifndef CONF_DAC1_REFRESH
#define CONF_DAC1_REFRESH 0
#define CONF_DAC1_REFRESH 2
#endif
// </h>

Expand Down
4 changes: 2 additions & 2 deletions ports/atmel-samd/asf4_conf/samd51/hpl_gclk_config.h
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
// Circuit Python SAMD51 clock tree:
// DFLL48M (with USBCRM on to sync with external USB ref) -> GCLK1, GCLK5
// GCLK1 (48MHz) -> peripherals
// GCLK5 (divided down to 2 MHz) -> DPLL0
// GCLK1 (48MHz) -> 48 MHz peripherals
// GCLK5 (48 MHz divided down to 2 MHz) -> DPLL0, DAC peripherals
// DPLL0 (multiplied up to 120 MHz) -> GCLK0, GCLK4 (output for monitoring)

// We'd like to use XOSC32K as a ref for DFLL48M on boards with a 32kHz crystal,
Expand Down
4 changes: 2 additions & 2 deletions ports/atmel-samd/asf4_conf/samd51/peripheral_clk_config.h
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Expand Up @@ -73,15 +73,15 @@
// <id> dac_gclk_selection
// <i> Select the clock source for DAC.
#ifndef CONF_GCLK_DAC_SRC
#define CONF_GCLK_DAC_SRC GCLK_PCHCTRL_GEN_GCLK1_Val
#define CONF_GCLK_DAC_SRC GCLK_PCHCTRL_GEN_GCLK5_Val
#endif

/**
* \def CONF_GCLK_DAC_FREQUENCY
* \brief DAC's Clock frequency
*/
#ifndef CONF_GCLK_DAC_FREQUENCY
#define CONF_GCLK_DAC_FREQUENCY 48000000
#define CONF_GCLK_DAC_FREQUENCY 2000000
#endif

// <y> EVSYS Channel 0 Clock Source
Expand Down
9 changes: 6 additions & 3 deletions ports/atmel-samd/common-hal/analogio/AnalogOut.c
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Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,7 @@
#include "atmel_start_pins.h"
#include "hal/include/hal_dac_sync.h"
#include "hpl/gclk/hpl_gclk_base.h"
#include "peripheral_clk_config.h"

#ifdef SAMD21
#include "hpl/pm/hpl_pm_base.h"
Expand Down Expand Up @@ -65,14 +66,16 @@ void common_hal_analogio_analogout_construct(analogio_analogout_obj_t* self,

#ifdef SAMD51
hri_mclk_set_APBDMASK_DAC_bit(MCLK);
hri_gclk_write_PCHCTRL_reg(GCLK, DAC_GCLK_ID, GCLK_PCHCTRL_GEN_GCLK5_Val | (1 << GCLK_PCHCTRL_CHEN_Pos));
#endif

#ifdef SAMD21
_pm_enable_bus_clock(PM_BUS_APBC, DAC);
_gclk_enable_channel(DAC_GCLK_ID, GCLK_CLKCTRL_GEN_GCLK0_Val);
#endif

// SAMD21: This clock should be <= 12 MHz, per datasheet section 47.6.3.
// SAMD51: This clock should be <= 350kHz, per datasheet table 37-6.
_gclk_enable_channel(DAC_GCLK_ID, CONF_GCLK_DAC_SRC);

// Don't double init the DAC on the SAMD51 when both outputs are in use. We use the free state
// of each output pin to determine DAC state.
int32_t result = ERR_NONE;
Expand Down Expand Up @@ -123,7 +126,7 @@ void common_hal_analogio_analogout_deinit(analogio_analogout_obj_t *self) {

void common_hal_analogio_analogout_set_value(analogio_analogout_obj_t *self,
uint16_t value) {
// Input is 16 bit so make sure and set LEFTADJ to 1 to it takes the top
// Input is 16 bit so make sure and set LEFTADJ to 1 so it takes the top
// bits. This is currently done in asf4_conf/*/hpl_dac_config.h.
dac_sync_write(&self->descriptor, self->channel, &value, 1);
}
Expand Down