This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration and management of the device's Frequency Meter functionality.
The following driver API modes are covered by this manual:
The following peripheral is used by this module:
The following devices can use this module:
The outline of this documentation is as follows:
There are no prerequisites for this module.
The module accurately measures the frequency of a clock by comparing it to a known reference clock as soon as the FREQM is enabled. Two generic clocks are used by the FREQM. The frequency of the measured clock is:
\[ f_{CLK\_MSR} = \frac{VALUE}{REFNUM} \times f_{CLK\_REF} \]
Ratio can be measured with 24-bit accuracy.
The FREQM has one interrupt source, which generates when a frequency measurement is done. It can be used to wake up the device from sleep modes.
This driver provides an interface for the FREQM functions on the device.
There are no special considerations for this module.
For extra information see Extra Information for FREQM Driver. This includes:
For a list of examples related to this driver, see Examples for FREQM Driver.
Modules | |
| Related Project(s) | |
| In this section you can find all the projects related to the SAM Frequency Meter (FREQM) Driver. | |
Data Structures | |
| struct | freqm_config |
| FREQM module configuration structure. More... | |
| struct | freqm_module |
| FREQM software device instance structure. More... | |
Typedefs | |
| typedef void(* | freqm_callback_t )(void) |
| Type definition for a FREQM module callback function. More... | |
Enumerations | |
| enum | freqm_callback { FREQM_CALLBACK_DONE = 0 } |
| Enum for possible callback types for the FREQM module. More... | |
| enum | freqm_callback_type { FREQM_CALLBACK_MEASURE_DONE = 0 } |
| FREQM callback type. More... | |
| enum | freqm_status { FREQM_STATUS_MEASURE_DONE = 0, FREQM_STATUS_MEASURE_BUSY = 1, FREQM_STATUS_CNT_OVERFLOW = 2 } |
| Enum for the possible status types for the FREQM module. More... | |
Functions | |
| static bool | freqm_is_syncing (void) |
| Determines if the hardware module(s) are currently synchronizing to the bus. More... | |
Variables | |
| struct freqm_module * | _freqm_instance |
Driver Initialization and Configuration | |
| enum status_code | freqm_init (struct freqm_module *const module_inst, Freqm *const hw, struct freqm_config *const config) |
| Initializes a hardware FREQM module instance. More... | |
| static void | freqm_get_config_defaults (struct freqm_config *const config) |
| Initializes all members of a FREQM configuration structure to safe defaults. More... | |
| static void | freqm_enable (struct freqm_module *const module_inst) |
| Enables a FREQM that was previously configured. More... | |
| static void | freqm_disable (struct freqm_module *const module_inst) |
| Disables a FREQM that was previously enabled. More... | |
Read FREQM Result | |
| static void | freqm_start_measure (struct freqm_module *const module) |
| Start a manual measurement process. More... | |
| static void | freqm_clear_overflow (struct freqm_module *const module) |
| Clears module overflow flag. More... | |
| enum freqm_status | freqm_get_result_value (struct freqm_module *const module_inst, uint32_t *result) |
| Read the measurement data result. More... | |
Callback Configuration and Initialization | |
| enum status_code | freqm_register_callback (struct freqm_module *const module, freqm_callback_t callback_func, enum freqm_callback callback_type) |
| Registers a callback. More... | |
| enum status_code | freqm_unregister_callback (struct freqm_module *module, enum freqm_callback callback_type) |
| Unregisters a callback. More... | |
Callback Enabling and Disabling | |
| static enum status_code | freqm_enable_callback (struct freqm_module *const module, const enum freqm_callback_type type) |
| Enable an FREQM callback. More... | |
| static enum status_code | freqm_disable_callback (struct freqm_module *const module, const enum freqm_callback_type type) |
| Disable an FREQM callback. More... | |
| typedef void(* freqm_callback_t)(void) |
Type definition for a FREQM module callback function.
| enum freqm_callback |
| enum freqm_callback_type |
| enum freqm_status |
|
inlinestatic |
|
inlinestatic |
Disables a FREQM that was previously enabled.
Disables Frequency Meter that was previously started via a call to freqm_enable().
| [in] | module_inst | Software instance for the Frequency Meter peripheral |
References Assert, and freqm_is_syncing().
Referenced by run_freqm_callback_read_test().
|
inlinestatic |
Disable an FREQM callback.
| [in,out] | module | Pointer to the software instance struct |
| [in] | type | Callback source type |
| STATUS_OK | The callback was enabled successfully |
| STATUS_ERR_INVALID_ARG | If an invalid callback type was supplied |
References Assert, FREQM_CALLBACK_MEASURE_DONE, STATUS_ERR_INVALID_ARG, STATUS_OK, system_interrupt_disable(), and SYSTEM_INTERRUPT_MODULE_FREQM.
Referenced by run_freqm_callback_read_test().
|
inlinestatic |
Enables a FREQM that was previously configured.
Enables Frequency Meter that was previously configured via a call to freqm_init().
| [in] | module_inst | Software instance for the Frequency Meter peripheral |
References Assert, and freqm_is_syncing().
Referenced by main(), and run_freqm_polling_read_test().
|
inlinestatic |
Enable an FREQM callback.
| [in,out] | module | Pointer to the software instance struct |
| [in] | type | Callback source type |
| STATUS_OK | The callback was enabled successfully |
| STATUS_ERR_INVALID_ARG | If an invalid callback type was supplied |
References Assert, FREQM_CALLBACK_MEASURE_DONE, STATUS_ERR_INVALID_ARG, STATUS_OK, system_interrupt_enable(), and SYSTEM_INTERRUPT_MODULE_FREQM.
Referenced by configure_freqm_callback(), and run_freqm_callback_read_test().
|
inlinestatic |
Initializes all members of a FREQM configuration structure to safe defaults.
Initializes all members of a given Frequency Meter configuration structure to safe known default values. This function should be called on all new instances of these configuration structures before being modified by the user application.
The default configuration is as follows:
| [in] | config | Configuration structure to initialize to default values |
References Assert, GCLK_GENERATOR_0, GCLK_GENERATOR_1, freqm_config::msr_clock_source, freqm_config::ref_clock_circles, and freqm_config::ref_clock_source.
Referenced by configure_freqm(), and run_freqm_polling_read_test().
| enum freqm_status freqm_get_result_value | ( | struct freqm_module *const | module_inst, |
| uint32_t * | result | ||
| ) |
Read the measurement data result.
Reads the measurement data result.
| [in] | module_inst | Pointer to the FREQM software instance struct |
| [out] | result | Pointer to store the result value in |
| FREQM_STATUS_MEASURE_DONE | Measurement result was retrieved successfully |
| FREQM_STATUS_MEASURE_BUSY | Measurement result was not ready |
| FREQM_STATUS_CNT_OVERFLOW | Measurement result was overflow |
References Assert, FREQM_STATUS_CNT_OVERFLOW, FREQM_STATUS_MEASURE_BUSY, and FREQM_STATUS_MEASURE_DONE.
Referenced by main(), run_freqm_callback_read_test(), and run_freqm_polling_read_test().
| enum status_code freqm_init | ( | struct freqm_module *const | module_inst, |
| Freqm *const | hw, | ||
| struct freqm_config *const | config | ||
| ) |
Initializes a hardware FREQM module instance.
Enables the clock and initializes the FREQM module, based on the given configuration values.
| [in,out] | module_inst | Pointer to the software module instance struct |
| [in] | hw | Pointer to the FREQM hardware module |
| [in] | config | Pointer to the FREQM configuration options struct |
| STATUS_OK | The module was initialized successfully |
References _freqm_instance, Assert, FREQM_GCLK_ID_REF, freqm_is_syncing(), i, module_inst, freqm_config::msr_clock_source, NULL, freqm_config::ref_clock_circles, freqm_config::ref_clock_source, system_gclk_chan_config::source_generator, STATUS_OK, system_apb_clock_set_mask(), SYSTEM_CLOCK_APB_APBA, system_gclk_chan_enable(), system_gclk_chan_get_config_defaults(), system_gclk_chan_set_config(), and system_gclk_gen_get_hz().
Referenced by configure_freqm(), and run_freqm_polling_read_test().
|
inlinestatic |
Determines if the hardware module(s) are currently synchronizing to the bus.
Checks to see if the underlying hardware peripheral module(s) are currently synchronizing across multiple clock domains to the hardware bus. This function can be used to delay further operations on a module until such time that it is ready, to prevent blocking delays for synchronization in the user application.
| false | If the module has completed synchronization |
| true | If the module synchronization is ongoing |
Referenced by freqm_disable(), freqm_enable(), and freqm_init().
| enum status_code freqm_register_callback | ( | struct freqm_module *const | module, |
| freqm_callback_t | callback_func, | ||
| enum freqm_callback | callback_type | ||
| ) |
Registers a callback.
Registers a callback function which is implemented by the user.
| [in] | module | Pointer to FREQM software instance struct |
| [in] | callback_func | Pointer to callback function |
| [in] | callback_type | Callback type given by an enum |
| STATUS_OK | The function exited successfully |
References Assert, FREQM_CALLBACK_TYPE_NUM, STATUS_ERR_INVALID_ARG, and STATUS_OK.
Referenced by configure_freqm_callback(), and run_freqm_callback_read_test().
|
inlinestatic |
Start a manual measurement process.
| [in] | module | Pointer to the FREQM software instance struct |
References Assert.
Referenced by main(), run_freqm_callback_read_test(), and run_freqm_polling_read_test().
| enum status_code freqm_unregister_callback | ( | struct freqm_module * | module, |
| enum freqm_callback | callback_type | ||
| ) |
Unregisters a callback.
Unregisters a callback function implemented by the user. The callback should be disabled before it is unregistered.
| [in] | module | Pointer to FREQM software instance struct |
| [in] | callback_type | Callback type given by an enum |
| STATUS_OK | The function exited successfully |
References Assert, FREQM_CALLBACK_TYPE_NUM, NULL, STATUS_ERR_INVALID_ARG, and STATUS_OK.
| struct freqm_module* _freqm_instance |
Referenced by FREQM_Handler(), and freqm_init().
1.8.5