RZ/A Flexible Software Package Documentation  Release v3.3.0

 
General Timer (r_gtm)

Functions

fsp_err_t R_GTM_Close (timer_ctrl_t *const p_ctrl)
 
fsp_err_t R_GTM_PeriodSet (timer_ctrl_t *const p_ctrl, uint32_t const period_counts)
 
fsp_err_t R_GTM_DutyCycleSet (timer_ctrl_t *const p_ctrl, uint32_t const duty_cycle_counts, uint32_t const pin)
 
fsp_err_t R_GTM_Reset (timer_ctrl_t *const p_ctrl)
 
fsp_err_t R_GTM_Start (timer_ctrl_t *const p_ctrl)
 
fsp_err_t R_GTM_Enable (timer_ctrl_t *const p_ctrl)
 
fsp_err_t R_GTM_Disable (timer_ctrl_t *const p_ctrl)
 
fsp_err_t R_GTM_InfoGet (timer_ctrl_t *const p_ctrl, timer_info_t *const p_info)
 
fsp_err_t R_GTM_StatusGet (timer_ctrl_t *const p_ctrl, timer_status_t *const p_status)
 
fsp_err_t R_GTM_Stop (timer_ctrl_t *const p_ctrl)
 
fsp_err_t R_GTM_Open (timer_ctrl_t *const p_ctrl, timer_cfg_t const *const p_cfg)
 
fsp_err_t R_GTM_CompareMatchSet (timer_ctrl_t *const p_ctrl, uint32_t const compare_match_value, timer_compare_match_t const match_channel)
 
fsp_err_t R_GTM_CallbackSet (timer_ctrl_t *const p_api_ctrl, void(*p_callback)(timer_callback_args_t *), void const *const p_context, timer_callback_args_t *const p_callback_memory)
 

Detailed Description

Driver for the GTM peripherals on RZ MPUs. This module implements the Timer Interface.

Overview

The GTM module can be used to count events, generate a periodic interrupt.

Features

The General timer has the following features:

Selecting a Timer

RZ MPUs have two timer peripherals: the Multi-Function Timer Pulse Unit 3 (MTU3a) and the General Timer (GTM). When selecting between them, consider these factors:

MTU3 GTM
Available ChannelsThe number of MTU3 channels is device specific. All currently supported MPUs have at least 8 MTU3 channels.All MPUs have 3 GTM channels.
Timer ResolutionAll MPUs have at least one 16-bit MTU3 timer.The GTM timers are 32-bit timers.
Clock SourceThe MTU3 runs off P0 clock with a configurable divider up to 1024.The GTM runs off P0 clock.

Configuration

Build Time Configurations for r_gtm

The following build time configurations are defined in fsp_cfg/r_gtm_cfg.h:

ConfigurationOptionsDefaultDescription
Parameter Checking
  • Default (BSP)
  • Enabled
  • Disabled
Default (BSP) If selected code for parameter checking is included in the build.

Configurations for Timers > Timer (r_gtm)

This module can be added to the Stacks tab via New Stack > Timers > Timer (r_gtm).

ConfigurationOptionsDefaultDescription
General > NameName must be a valid C symbolg_timer0 Module name.
General > ChannelChannel number does not exist0 Physical hardware channel.
General > Mode
  • Periodic
  • One-Shot
Periodic Mode selection. Note: One-shot mode is implemented in software. ISR's must be enabled for one shot even if callback is unused.
General > PeriodValue must be non-negative1 Specify the timer period based on the selected unit.

Valid input value range:
- When 'Raw Counts' is selected in 'Period Unit', set the value to 0x00000001~0x100000000
- When other item is selected in 'Period Unit', set the value to (1 / count clock) ~ (0x100000000 / count clock)

If the input value is exceeded valid range, the ERROR will be shown in hal_data.c.
General > Period Unit
  • Raw Counts
  • Nanoseconds
  • Microseconds
  • Milliseconds
  • Seconds
  • Hertz
  • Kilohertz
Milliseconds Unit of the period specified above
General > Count SourceP0CLKP0CLK GTM counter clock source.
Interrupts > CallbackName must be a valid C symbolNULL A user callback function. If this callback function is provided, it is called from the interrupt service routine (ISR) each time the timer period elapses.
Interrupts > Underflow Interrupt PriorityIllegal interrupt priority level24 Timer interrupt priority(0-31). Note: If you specify the lowest priority (i.e.,31), no interrupt will occur.
Interrupts > Generate at Start
  • Disable
  • Enable
Disable Controls enabling or disabling of generates OSTMnTINT interrupt at starts
Extra Features > GTM Mode
  • Interval timer mode
  • Free-running comparison mode
Interval timer mode GTM Count Mode (Interval timer mode or Free-running comparison mode)

Clock Configuration

The GTM clock is based on the P0 clock frequency. You can set the P0 clock frequency using the Clocks tab of the Configuration editor.

Timer Period

The Configuration editor will automatically calculate the period count value based on the selected period time, units.

When the selected unit is "Raw counts", the maximum allowed period setting varies depending on the selected clock source:

Clock source Maximum period (counts)
P0 clock 0x100000000
Note
Though the GTM is a 32-bit timer, because the period interrupt occurs when the counter underflows, setting the period register to 0 results in an effective period of 1 count. For this reason all user-provided raw count values reflect the actual number of period counts (not the raw register values).

Usage Notes

Interval Timer Mode

In this mode, the timer counts down from the value specified in the compare match register. An interrupt request is generated when the counter reaches 0x0000_0000.

Free-Running Comparison Mode

In this mode, the counter counts up from 0x0000_0000 to 0xFFFF_FFFF. An interrupt request is output when the current value of the counter matches the value of the compare match register.

Updating Period

The period is updated after the next counter overflow or underflow after calling R_GTM_PeriodSet().

One-Shot Mode

The GTM timer does not support one-shot mode natively. One-shot mode is achieved by stopping the timer in the interrupt service routine before the callback is called. If the interrupt is not serviced before the timer period expires again, the timer generates more than one event. The callback is only called once in this case.

Examples of periodic signals that can be generated by this module are shown below:

Examples

GTM Basic Example

This is a basic example of minimal use of the GTM in an application.

void gtm_basic_example (void)
{
fsp_err_t err = FSP_SUCCESS;
/* Initializes the module. */
err = R_GTM_Open(&g_timer_ctrl, &g_timer_cfg);
/* Handle any errors. This function should be defined by the user. */
assert(FSP_SUCCESS == err);
/* Start the timer. */
(void) R_GTM_Start(&g_timer_ctrl);
}

GTM Callback Example

This is an example of a timer callback.

/* Example callback called when timer expires. */
void timer_callback (timer_callback_args_t * p_args)
{
if (TIMER_EVENT_CYCLE_END == p_args->event)
{
/* Add application code to be called periodically here. */
}
}

GTM Free Running Counter Example

To use the GTM as a free running counter, select Free-Running Comparison Mode.

void gtm_counter_example (void)
{
fsp_err_t err = FSP_SUCCESS;
/* Initializes the module. */
err = R_GTM_Open(&g_timer_ctrl, &g_timer_cfg);
/* Handle any errors. This function should be defined by the user. */
assert(FSP_SUCCESS == err);
/* Start the timer. */
(void) R_GTM_Start(&g_timer_ctrl);
/* (Optional) Stop the timer. */
(void) R_GTM_Stop(&g_timer_ctrl);
/* Read the current counter value. Counter value is in status.counter. */
(void) R_GTM_StatusGet(&g_timer_ctrl, &status);
}

GTM Period Update Example

This is an example of updating the period.

#define GTM_EXAMPLE_MSEC_PER_SEC (1000)
#define GTM_EXAMPLE_DESIRED_PERIOD_MSEC (20)
/* This example shows how to calculate a new period value at runtime. */
void gtm_period_calculation_example (void)
{
fsp_err_t err = FSP_SUCCESS;
/* Initializes the module. */
err = R_GTM_Open(&g_timer_ctrl, &g_timer_cfg);
/* Handle any errors. This function should be defined by the user. */
assert(FSP_SUCCESS == err);
/* Start the timer. */
(void) R_GTM_Start(&g_timer_ctrl);
/* Get the source clock frequency (in Hz). There are several ways to do this in FSP:
* - Use the R_GTM_InfoGet function (it accounts for the clock source and divider).
* - Calculate the current P0 clock frequency using R_FSP_SystemClockHzGet(FSP_PRIV_CLOCK_P0CLK).
*
* This example uses the last option (R_FSP_SystemClockHzGet).
*/
uint32_t timer_freq_hz = R_FSP_SystemClockHzGet(FSP_PRIV_CLOCK_P0CLK);
/* Calculate the desired period based on the current clock. Note that this calculation could overflow if the
* desired period is larger than UINT32_MAX / p0clk_freq_hz. A cast to uint64_t is used to prevent this. */
uint32_t period_counts =
(uint32_t) (((uint64_t) timer_freq_hz * gtm_EXAMPLE_DESIRED_PERIOD_MSEC) / gtm_EXAMPLE_MSEC_PER_SEC);
/* Set the calculated period. */
err = R_GTM_PeriodSet(&g_timer_ctrl, period_counts);
assert(FSP_SUCCESS == err);
}

Data Structures

struct  gtm_instance_ctrl_t
 
struct  gtm_extended_cfg_t
 

Enumerations

enum  gtm_giws_type_t
 
enum  gtm_timer_mode_t
 

Data Structure Documentation

◆ gtm_instance_ctrl_t

struct gtm_instance_ctrl_t

Channel control block. DO NOT INITIALIZE. Initialization occurs when timer_api_t::open is called.

◆ gtm_extended_cfg_t

struct gtm_extended_cfg_t

Optional GTM extension data structure.

Enumeration Type Documentation

◆ gtm_giws_type_t

Optional GTM interrupt setting

Enumerator
GTM_GIWS_TYPE_DISABLED 

Do not generate interrupt when timer started.

GTM_GIWS_TYPE_ENABLED 

Generates interrupt when timer started.

◆ gtm_timer_mode_t

Optional GTM timer mode setting

Enumerator
GTM_TIMER_MODE_INTERVAL 

Use interval timer mode.

GTM_TIMER_MODE_FREERUN 

Use free-running comparison mode.

Function Documentation

◆ R_GTM_Close()

fsp_err_t R_GTM_Close ( timer_ctrl_t *const  p_ctrl)

Stops counter, disables interrupts, disables output pins, and clears internal driver data. Implements timer_api_t::close.

Return values
FSP_SUCCESSTimer closed.
FSP_ERR_ASSERTIONp_ctrl is NULL.
FSP_ERR_NOT_OPENThe instance control structure is not opened.

◆ R_GTM_PeriodSet()

fsp_err_t R_GTM_PeriodSet ( timer_ctrl_t *const  p_ctrl,
uint32_t const  period_counts 
)

Updates period. The new period is updated immediately and the counter is reset to the maximum value. Implements timer_api_t::periodSet.

Warning
If periodic output is used, the duty cycle buffer registers are updated after the period buffer register. If this function is called while the timer is running and an GTM underflow occurs during processing, the duty cycle will not be the desired 50% duty cycle until the counter underflow after processing completes.
Stop the timer before calling this function if one-shot output is used.
Return values
FSP_SUCCESSPeriod value updated.
FSP_ERR_ASSERTIONA required pointer was NULL, or the period was not in the valid range of 1 to 0xFFFF.
FSP_ERR_NOT_OPENThe instance control structure is not opened.

◆ R_GTM_DutyCycleSet()

fsp_err_t R_GTM_DutyCycleSet ( timer_ctrl_t *const  p_ctrl,
uint32_t const  duty_cycle_counts,
uint32_t const  pin 
)

Updates duty cycle. If the timer is counting, the new duty cycle is reflected after the next counter underflow. Implements timer_api_t::dutyCycleSet.

Return values
FSP_ERR_UNSUPPORTED

◆ R_GTM_Reset()

fsp_err_t R_GTM_Reset ( timer_ctrl_t *const  p_ctrl)

Resets the counter value to the period minus one. Implements timer_api_t::reset.

Return values
FSP_ERR_UNSUPPORTEDSelected function not supported by this module.

◆ R_GTM_Start()

fsp_err_t R_GTM_Start ( timer_ctrl_t *const  p_ctrl)

Starts timer. Implements timer_api_t::start.

Return values
FSP_SUCCESSTimer started.
FSP_ERR_ASSERTIONp_ctrl is null.
FSP_ERR_NOT_OPENThe instance control structure is not opened.

◆ R_GTM_Enable()

fsp_err_t R_GTM_Enable ( timer_ctrl_t *const  p_ctrl)

Enables external event triggers that start, stop, clear, or capture the counter. Implements timer_api_t::enable.

Return values
FSP_ERR_UNSUPPORTEDSelected function not supported by this module.

◆ R_GTM_Disable()

fsp_err_t R_GTM_Disable ( timer_ctrl_t *const  p_ctrl)

Disables external event triggers that start, stop, clear, or capture the counter. Implements timer_api_t::disable.

Return values
FSP_ERR_UNSUPPORTEDSelected function not supported by this module.

◆ R_GTM_InfoGet()

fsp_err_t R_GTM_InfoGet ( timer_ctrl_t *const  p_ctrl,
timer_info_t *const  p_info 
)

Gets timer information and store it in provided pointer p_info. Implements timer_api_t::infoGet.

Return values
FSP_SUCCESSPeriod, count direction, and frequency stored in p_info.
FSP_ERR_ASSERTIONA required pointer is NULL.
FSP_ERR_NOT_OPENThe instance control structure is not opened.

◆ R_GTM_StatusGet()

fsp_err_t R_GTM_StatusGet ( timer_ctrl_t *const  p_ctrl,
timer_status_t *const  p_status 
)

Retrieves the current state and counter value stores them in p_status. Implements timer_api_t::statusGet.

Return values
FSP_SUCCESSCurrent status and counter value provided in p_status.
FSP_ERR_ASSERTIONA required pointer is NULL.
FSP_ERR_NOT_OPENThe instance control structure is not opened.

◆ R_GTM_Stop()

fsp_err_t R_GTM_Stop ( timer_ctrl_t *const  p_ctrl)

Stops the timer. Implements timer_api_t::stop.

Return values
FSP_SUCCESSTimer stopped.
FSP_ERR_ASSERTIONp_ctrl was NULL.
FSP_ERR_NOT_OPENThe instance control structure is not opened.

◆ R_GTM_Open()

fsp_err_t R_GTM_Open ( timer_ctrl_t *const  p_ctrl,
timer_cfg_t const *const  p_cfg 
)

Initializes the GTM module instance. Implements timer_api_t::open.

The GTM hardware does not support one-shot functionality natively. The one-shot feature is therefore implemented in the GTM HAL layer. For a timer configured as a one-shot timer, the timer is stopped upon the first timer expiration.

The GTM implementation of the general timer can accept an optional gtm_extended_cfg_t extension parameter. For GTM, the extension specifies the clock to be used as timer source and the output pin configurations. If the extension parameter is not specified (NULL), the default clock P0CLK is used and the output pins are disabled.

Return values
FSP_SUCCESSInitialization was successful and timer has started.
FSP_ERR_ASSERTIONA required input pointer is NULL or the period is not in the valid range of 1 to 0xFFFF.
FSP_ERR_ALREADY_OPENR_GTM_Open has already been called for this p_ctrl.
FSP_ERR_IRQ_BSP_DISABLEDA required interrupt has not been enabled in the vector table.
FSP_ERR_IP_CHANNEL_NOT_PRESENTRequested channel number is not available on GTM.

◆ R_GTM_CompareMatchSet()

fsp_err_t R_GTM_CompareMatchSet ( timer_ctrl_t *const  p_ctrl,
uint32_t const  compare_match_value,
timer_compare_match_t const  match_channel 
)

Placeholder for unsupported compareMatch function. Implements timer_api_t::compareMatchSet.

Return values
FSP_ERR_UNSUPPORTEDGTM compare match is not supported.

◆ R_GTM_CallbackSet()

fsp_err_t R_GTM_CallbackSet ( timer_ctrl_t *const  p_api_ctrl,
void(*)(timer_callback_args_t *)  p_callback,
void const *const  p_context,
timer_callback_args_t *const  p_callback_memory 
)

Updates the user callback with the option to provide memory for the callback argument structure. Implements timer_api_t::callbackSet.

Return values
FSP_SUCCESSCallback updated successfully.
FSP_ERR_ASSERTIONA required pointer is NULL.
FSP_ERR_NOT_OPENThe control block has not been opened.
FSP_ERR_NO_CALLBACK_MEMORYp_callback is non-secure and p_callback_memory is either secure or NULL.