This section introduces the General Purpose Counter(GPC) APIs including terms and acronyms, supported features, software architecture, details on how to use this driver, GPC function groups, enums, structures and functions. More...

Overview

This section introduces the General Purpose Counter(GPC) APIs including terms and acronyms, supported features, software architecture, details on how to use this driver, GPC function groups, enums, structures and functions.

Terms and acronyms

Terms	Details
GPC	General Purpose Counter(GPC) captures pulses using raising or falling edge, and counts the number of pulses.
GPIO	For an introduction to General Purpose Inputs-Outputs, please refer to the GPIO module in HAL.
NVIC	The Nested Vectored Interrupt Controller (NVIC) is the interrupt controller of ARM Cortex-M. For more details, please refer to NVIC introduction in ARM Cortex-M4 Processor Technical Reference Manual .

Supported features

This module is a generic design to capture the number of pulse waveforms. The GPC is to record pulses number. Compared with the EINT to capture pulses, the EINT will generate interrupt, and it occupies the cpu resource. They are two different scenarios.

Support normal mode.
In this mode, there is no interrupt, and the register configuration is the default parameter of driver, user cannot modify it. This mode is usually used for non-urgent pulse-counting. Call hal_gpc_get_and_clear_count() function to check the counter values, when the GPC module is enabled.

How to use this driver

Using GPC normal mode.
To use the GPC driver in a normal mode, look up GPIO datasheet to decide which GPIOs should be selected to pinmux to GPC pin, then call hal_pinmux_set_function to select the pinmux function. After the pinmux setting, hal_gpc_get_running_status() must be called to check the GPC status. If the status is HAL_GPC_STATUS_BUSY, user should wait till the status becomes HAL_GPC_STATUS_IDLE. Once the pulses are captured, always call hal_gpc_deinit() to release the GPC resource, to enable other users to use the GPC module.
Use GPC with normal mode.
- Step1: Call hal_gpio_init() to initialize the pin. For mode details about hal_gpio_init please refer to GPIO module in HAL.
- Step2: Call hal_pinmux_set_function to set GPC pinmux. For mode details about hal_pinmux_set_function please refer to GPIO module in HAL.
- Step3: Call hal_gpc_init() to configue the GPC hardware.
- Step4: Call hal_gpc_enable() to start to capture pulses.
- Step5: Call hal_gpc_get_and_clear_count() to get GPC counter value.
- Step6: Call hal_gpc_disable() to stop capturing pulses.
- Step7: Call hal_gpc_deinit() to to deinitialize the GPC module if it's no longer in use.
- Sample code:
  hal_gpc_running_status_t running_status;
  hal_gpc_status_t ret_status;
  uint32_t count_value;
  hal_gpc_config_t gpc_config;
  gpc_config.edge = HAL_GPC_EDGE_RAISING;
  hal_gpio_init(HAL_GPIO_33);
  //Call hal_pinmux_set_function() to set GPIO pinmux, for more information, please reference hal_pinmux_define.h
  //function_index = HAL_GPIO_33_PULSE_CNT, need not to configure pinmux if EPT tool is used.
  hal_pinmux_set_function(HAL_GPIO_33, function_index); //set pinmux
  //initialize GPC hardware with driver default configuration
  if(HAL_GPC_STATUS_OK != hal_gpc_init(HAL_GPC_0, &gpc_config) {
  //error handle
  }
  hal_gpc_enable(HAL_GPC_0); //start to capture pulses
  //.... //capture pulse
  //....
  hal_gpc_get_and_clear_count(HAL_GPC_0,&count_value); //get counter value and clear it.
  hal_gpc_disable(HAL_GPC_0); //stop capturing pulses
  hal_gpc_deinit(HAL_GPC_0); //if no longer in use.

Functions
hal_gpc_status_t	hal_gpc_init (hal_gpc_port_t gpc_port, const hal_gpc_config_t *gpc_config)
	This function is used to initialize the GPC base environment. More...

hal_gpc_status_t	hal_gpc_deinit (hal_gpc_port_t gpc_port)
	Deinitilize the GPC. More...

hal_gpc_status_t	hal_gpc_enable (hal_gpc_port_t gpc_port)
	Enable the GPC module, after that the GPC can start to capture the pulses. More...

hal_gpc_status_t	hal_gpc_disable (hal_gpc_port_t gpc_port)
	Disable the GPC module, after that the GPC stop capturing the pulses. More...

hal_gpc_status_t	hal_gpc_get_running_status (hal_gpc_port_t gpc_port, hal_gpc_running_status_t *running_state)
	To get the port that you specified is idle or busy. More...

hal_gpc_status_t	hal_gpc_get_and_clear_count (hal_gpc_port_t gpc_port, uint32_t *count)
	Get the current count value, then clear count register to 0. More...

Modules
	Enum

	Struct

	Typedef

Function Documentation

hal_gpc_status_t hal_gpc_deinit ( hal_gpc_port_t gpc_port )

Deinitilize the GPC.

After this function, the callback is cleared, clock power is closed, the GPC module disabled.

Parameters

[in] gpc_port is the port number.

Returns: HAL_GPC_STATUS_OK, if OK.
HAL_GPC_STATUS_ERROR_PORT, the gpc_port value is wrong.

See also: hal_gpc_init()

hal_gpc_status_t hal_gpc_disable ( hal_gpc_port_t gpc_port )

Disable the GPC module, after that the GPC stop capturing the pulses.

If user do not call hal_gpc_get_and_clear_count(), the value in count register will be kept until clear it.

Parameters

[in] gpc_port is the port number.

Returns: HAL_GPC_STATUS_OK, if OK.
HAL_GPC_STATUS_ERROR_PORT, the gpc_port value is wrong.

See also: hal_gpc_enable().

hal_gpc_status_t hal_gpc_enable ( hal_gpc_port_t gpc_port )

Enable the GPC module, after that the GPC can start to capture the pulses.

Parameters

[in] gpc_port is the port number.

Returns: HAL_GPC_STATUS_OK, if OK.
HAL_GPC_STATUS_ERROR_PORT, the gpc_port value is wrong.

See also: hal_gpc_disable().

hal_gpc_status_t hal_gpc_get_and_clear_count	(	hal_gpc_port_t	gpc_port,
		uint32_t *	count
	)

Get the current count value, then clear count register to 0.

Parameters

[in]	gpc_port	is the port number.
[out]	count	is a pointer that to get count value.

Returns: HAL_GPC_STATUS_OK, if OK.
HAL_GPC_STATUS_ERROR_PORT, the gpc_port value is wrong.

hal_gpc_status_t hal_gpc_get_running_status	(	hal_gpc_port_t	gpc_port,
		hal_gpc_running_status_t *	running_state
	)

To get the port that you specified is idle or busy.

Parameters

[in]	gpc_port	is the port number.
[out]	running_state	is a pointer to get status value. For mode details, please refer to hal_gpc_running_status_t.

Returns: HAL_GPC_STATUS_OK, if OK.
HAL_GPC_STATUS_ERROR_PORT, the gpc_port value is wrong.

hal_gpc_status_t hal_gpc_init	(	hal_gpc_port_t	gpc_port,
		const hal_gpc_config_t *	gpc_config
	)

This function is used to initialize the GPC base environment.

Parameters

[in]	gpc_port	is the port number.
[in]	gpc_config	is the pointer of config. For mode details please, refer to hal_gpc_config_t.

Returns: HAL_GPC_STATUS_OK, if OK.
HAL_GPC_STATUS_ERROR_PORT, the gpc_port value is wrong.

See also: hal_gpc_deinit()

Overview

Terms and acronyms

Supported features

How to use this driver

Functions

Modules

Function Documentation