Low-level hardware timer API. More...
Macros | |
#define | TIMER_ALARM_IRQ_NUM(timer, alarm_num) |
Returns the irq_num_t for the alarm interrupt from the given alarm on the given timer instance. More... | |
#define | TIMER_ALARM_NUM_FROM_IRQ(irq_num) |
Returns the alarm number from an \irq_num_t. See TIMER_INSTANCE_NUM_FROM_IRQ to get the timer instance number. More... | |
#define | TIMER_NUM_FROM_IRQ(irq_num) |
Returns the alarm number from an \irq_num_t. See TIMER_INSTANCE_NUM_FROM_IRQ to get the alarm number. More... | |
#define | PICO_DEFAULT_TIMER 0 |
The default timer instance number of the timer instance used for APIs that don't take an explicit timer instance On RP2040 this must be 0 as there is only one timer instance On RP2040 this may be set to 0 or 1 . | |
#define | PICO_DEFAULT_TIMER_INSTANCE() |
Returns the default timer instance on the platform based on the setting of PICO_DEFAULT_TIMER. More... | |
Typedefs | |
typedef void(* | hardware_alarm_callback_t) (uint alarm_num) |
Functions | |
static uint32_t | timer_time_us_32 (timer_hw_t *timer) |
Return a 32 bit timestamp value in microseconds for a given timer instance. More... | |
static uint32_t | time_us_32 (void) |
Return a 32 bit timestamp value in microseconds for the default timer instance. More... | |
uint64_t | timer_time_us_64 (timer_hw_t *timer) |
Return the current 64 bit timestamp value in microseconds for a given timer instance. More... | |
uint64_t | time_us_64 (void) |
Return the current 64 bit timestamp value in microseconds for the default timer instance. More... | |
void | timer_busy_wait_us_32 (timer_hw_t *timer, uint32_t delay_us) |
Busy wait wasting cycles for the given (32 bit) number of microseconds using the given timer instance. More... | |
void | busy_wait_us_32 (uint32_t delay_us) |
Busy wait wasting cycles for the given (32 bit) number of microseconds using the default timer instance. More... | |
void | timer_busy_wait_us (timer_hw_t *timer, uint64_t delay_us) |
Busy wait wasting cycles for the given (64 bit) number of microseconds using the given timer instance. More... | |
void | busy_wait_us (uint64_t delay_us) |
Busy wait wasting cycles for the given (64 bit) number of microseconds using the default timer instance. More... | |
void | timer_busy_wait_ms (timer_hw_t *timer, uint32_t delay_ms) |
Busy wait wasting cycles for the given number of milliseconds using the given timer instance. More... | |
void | busy_wait_ms (uint32_t delay_ms) |
Busy wait wasting cycles for the given number of milliseconds using the default timer instance. More... | |
void | timer_busy_wait_until (timer_hw_t *timer, absolute_time_t t) |
Busy wait wasting cycles until after the specified timestamp using the given timer instance. More... | |
void | busy_wait_until (absolute_time_t t) |
Busy wait wasting cycles until after the specified timestamp using the default timer instance. More... | |
static bool | timer_time_reached (timer_hw_t *timer, absolute_time_t t) |
Check if the specified timestamp has been reached on the given timer instance. More... | |
static bool | time_reached (absolute_time_t t) |
Check if the specified timestamp has been reached on the default timer instance. More... | |
void | timer_hardware_alarm_claim (timer_hw_t *timer, uint alarm_num) |
cooperatively claim the use of this hardware alarm_num on the given timer instance More... | |
void | hardware_alarm_claim (uint alarm_num) |
cooperatively claim the use of this hardware alarm_num on the default timer instance More... | |
int | timer_hardware_alarm_claim_unused (timer_hw_t *timer, bool required) |
cooperatively claim the use of a hardware alarm_num on the given timer instance More... | |
int | hardware_alarm_claim_unused (bool required) |
cooperatively claim the use of a hardware alarm_num on the default timer instance More... | |
void | timer_hardware_alarm_unclaim (timer_hw_t *timer, uint alarm_num) |
cooperatively release the claim on use of this hardware alarm_num on the given timer instance More... | |
void | hardware_alarm_unclaim (uint alarm_num) |
cooperatively release the claim on use of this hardware alarm_num on the default timer instance More... | |
bool | timer_hardware_alarm_is_claimed (timer_hw_t *timer, uint alarm_num) |
Determine if a hardware alarm has been claimed on the given timer instance. More... | |
bool | hardware_alarm_is_claimed (uint alarm_num) |
Determine if a hardware alarm has been claimed on the default timer instance. More... | |
void | timer_hardware_alarm_set_callback (timer_hw_t *timer, uint alarm_num, hardware_alarm_callback_t callback) |
Enable/Disable a callback for a hardware alarm for a given timer instance on this core. More... | |
void | hardware_alarm_set_callback (uint alarm_num, hardware_alarm_callback_t callback) |
Enable/Disable a callback for a hardware alarm on the default timer instance on this core. More... | |
bool | timer_hardware_alarm_set_target (timer_hw_t *timer, uint alarm_num, absolute_time_t t) |
Set the current target for a specific hardware alarm on the given timer instance. More... | |
bool | hardware_alarm_set_target (uint alarm_num, absolute_time_t t) |
Set the current target for the specified hardware alarm on the default timer instance. More... | |
void | timer_hardware_alarm_cancel (timer_hw_t *timer, uint alarm_num) |
Cancel an existing target (if any) for a specific hardware_alarm on the given timer instance. More... | |
void | hardware_alarm_cancel (uint alarm_num) |
Cancel an existing target (if any) for the specified hardware_alarm on the default timer instance. More... | |
void | timer_hardware_alarm_force_irq (timer_hw_t *timer, uint alarm_num) |
Force and IRQ for a specific hardware alarm on the given timer instance. More... | |
void | hardware_alarm_force_irq (uint alarm_num) |
Force and IRQ for a specific hardware alarm on the default timer instance. More... | |
static uint | timer_hardware_alarm_get_irq_num (__unused timer_hw_t *timer, uint alarm_num) |
Returns the irq_num_t for the alarm interrupt from the given alarm on the given timer instance. More... | |
static uint | hardware_alarm_get_irq_num (timer_hw_t *timer, uint alarm_num) |
Returns the irq_num_t for the alarm interrupt from the given alarm on the default timer instance. More... | |
static uint | timer_get_index (timer_hw_t *timer) |
Returns the timer number for a timer instance. More... | |
static timer_hw_t * | timer_get_instance (uint timer_num) |
Returns the timer instance with the given timer number. More... | |
Low-level hardware timer API.
This API provides medium level access to the timer HW. See also pico_time which provides higher levels functionality using the hardware timer.
The timer peripheral on RP-series microcontrollers supports the following features:
On RP2040, by default the timer uses a one microsecond reference that is generated in the Watchdog (see RP2040 Datasheet Section 4.8.2) which is derived from the clk_ref.
On RP2350, by default the timer uses a one microsecond reference that is generated by the tick block (see RP2350 Datasheet Section 8.5)
The timer has 4 alarms, and can output a separate interrupt for each alarm. The alarms match on the lower 32 bits of the 64 bit counter which means they can be fired a maximum of 2^32 microseconds into the future. This is equivalent to:
The timer is expected to be used for short sleeps, if you want a longer alarm see the hardware_rtc functions.
#define PICO_DEFAULT_TIMER_INSTANCE | ( | ) |
Returns the default timer instance on the platform based on the setting of PICO_DEFAULT_TIMER.
Note this macro is intended to resolve at compile time, and does no parameter checking
#define TIMER_ALARM_IRQ_NUM | ( | timer, | |
alarm_num | |||
) |
Returns the irq_num_t for the alarm interrupt from the given alarm on the given timer instance.
Note this macro is intended to resolve at compile time, and does no parameter checking
#define TIMER_ALARM_NUM_FROM_IRQ | ( | irq_num | ) |
Returns the alarm number from an \irq_num_t. See TIMER_INSTANCE_NUM_FROM_IRQ to get the timer instance number.
Note this macro is intended to resolve at compile time, and does no parameter checking
#define TIMER_NUM_FROM_IRQ | ( | irq_num | ) |
Returns the alarm number from an \irq_num_t. See TIMER_INSTANCE_NUM_FROM_IRQ to get the alarm number.
Note this macro is intended to resolve at compile time, and does no parameter checking
typedef void(* hardware_alarm_callback_t) (uint alarm_num) |
Callback function type for hardware alarms
alarm_num | the hardware alarm number |
void busy_wait_ms | ( | uint32_t | delay_ms | ) |
Busy wait wasting cycles for the given number of milliseconds using the default timer instance.
delay_ms | delay amount in milliseconds |
void busy_wait_until | ( | absolute_time_t | t | ) |
Busy wait wasting cycles until after the specified timestamp using the default timer instance.
t | Absolute time to wait until |
void busy_wait_us | ( | uint64_t | delay_us | ) |
Busy wait wasting cycles for the given (64 bit) number of microseconds using the default timer instance.
delay_us | delay amount in microseconds |
void busy_wait_us_32 | ( | uint32_t | delay_us | ) |
Busy wait wasting cycles for the given (32 bit) number of microseconds using the default timer instance.
delay_us | delay amount in microseconds |
void hardware_alarm_cancel | ( | uint | alarm_num | ) |
Cancel an existing target (if any) for the specified hardware_alarm on the default timer instance.
alarm_num | the hardware alarm number |
void hardware_alarm_claim | ( | uint | alarm_num | ) |
cooperatively claim the use of this hardware alarm_num on the default timer instance
This method hard asserts if the hardware alarm is currently claimed.
alarm_num | the hardware alarm to claim |
int hardware_alarm_claim_unused | ( | bool | required | ) |
cooperatively claim the use of a hardware alarm_num on the default timer instance
This method attempts to claim an unused hardware alarm
required | if true the function will panic if none are available |
void hardware_alarm_force_irq | ( | uint | alarm_num | ) |
Force and IRQ for a specific hardware alarm on the default timer instance.
This method will forcibly make sure the current alarm callback (if present) for the hardware alarm is called from an IRQ context after this call. If an actual callback is due at the same time then the callback may only be called once.
Calling this method does not otherwise interfere with regular callback operations.
alarm_num | the hardware alarm number |
|
inlinestatic |
Returns the irq_num_t for the alarm interrupt from the given alarm on the default timer instance.
timer | the timer instance |
alarm_num | the alarm number |
bool hardware_alarm_is_claimed | ( | uint | alarm_num | ) |
Determine if a hardware alarm has been claimed on the default timer instance.
alarm_num | the hardware alarm number |
void hardware_alarm_set_callback | ( | uint | alarm_num, |
hardware_alarm_callback_t | callback | ||
) |
Enable/Disable a callback for a hardware alarm on the default timer instance on this core.
This method enables/disables the alarm IRQ for the specified hardware alarm on the calling core, and set the specified callback to be associated with that alarm.
This callback will be used for the timeout set via hardware_alarm_set_target
alarm_num | the hardware alarm number |
callback | the callback to install, or NULL to unset |
bool hardware_alarm_set_target | ( | uint | alarm_num, |
absolute_time_t | t | ||
) |
Set the current target for the specified hardware alarm on the default timer instance.
This will replace any existing target
alarm_num | the hardware alarm number |
t | the target timestamp |
void hardware_alarm_unclaim | ( | uint | alarm_num | ) |
cooperatively release the claim on use of this hardware alarm_num on the default timer instance
alarm_num | the hardware alarm to unclaim |
|
inlinestatic |
Check if the specified timestamp has been reached on the default timer instance.
t | Absolute time to compare against current time |
|
inlinestatic |
Return a 32 bit timestamp value in microseconds for the default timer instance.
Returns the low 32 bits of the hardware timer.
uint64_t time_us_64 | ( | void | ) |
Return the current 64 bit timestamp value in microseconds for the default timer instance.
Returns the full 64 bits of the hardware timer. The pico_time and other functions rely on the fact that this value monotonically increases from power up. As such it is expected that this value counts upwards and never wraps (we apologize for introducing a potential year 5851444 bug).
void timer_busy_wait_ms | ( | timer_hw_t * | timer, |
uint32_t | delay_ms | ||
) |
Busy wait wasting cycles for the given number of milliseconds using the given timer instance.
timer | the timer instance |
delay_ms | delay amount in milliseconds |
void timer_busy_wait_until | ( | timer_hw_t * | timer, |
absolute_time_t | t | ||
) |
Busy wait wasting cycles until after the specified timestamp using the given timer instance.
timer | the timer instance |
t | Absolute time to wait until |
void timer_busy_wait_us | ( | timer_hw_t * | timer, |
uint64_t | delay_us | ||
) |
Busy wait wasting cycles for the given (64 bit) number of microseconds using the given timer instance.
timer | the timer instance |
delay_us | delay amount in microseconds |
void timer_busy_wait_us_32 | ( | timer_hw_t * | timer, |
uint32_t | delay_us | ||
) |
Busy wait wasting cycles for the given (32 bit) number of microseconds using the given timer instance.
timer | the timer instance |
delay_us | delay amount in microseconds |
Busy wait wasting cycles for the given (32 bit) number of microseconds using the given timer instance.
|
inlinestatic |
Returns the timer number for a timer instance.
timer | the timer instance |
|
inlinestatic |
Returns the timer instance with the given timer number.
timer_num | the timer number |
void timer_hardware_alarm_cancel | ( | timer_hw_t * | timer, |
uint | alarm_num | ||
) |
Cancel an existing target (if any) for a specific hardware_alarm on the given timer instance.
timer | the timer instance |
alarm_num | the hardware alarm number |
void timer_hardware_alarm_claim | ( | timer_hw_t * | timer, |
uint | alarm_num | ||
) |
cooperatively claim the use of this hardware alarm_num on the given timer instance
This method hard asserts if the hardware alarm is currently claimed.
timer | the timer instance |
alarm_num | the hardware alarm to claim |
int timer_hardware_alarm_claim_unused | ( | timer_hw_t * | timer, |
bool | required | ||
) |
cooperatively claim the use of a hardware alarm_num on the given timer instance
This method attempts to claim an unused hardware alarm
timer | the timer instance |
required | if true the function will panic if none are available |
void timer_hardware_alarm_force_irq | ( | timer_hw_t * | timer, |
uint | alarm_num | ||
) |
Force and IRQ for a specific hardware alarm on the given timer instance.
This method will forcibly make sure the current alarm callback (if present) for the hardware alarm is called from an IRQ context after this call. If an actual callback is due at the same time then the callback may only be called once.
Calling this method does not otherwise interfere with regular callback operations.
timer | the timer instance |
alarm_num | the hardware alarm number |
|
inlinestatic |
Returns the irq_num_t for the alarm interrupt from the given alarm on the given timer instance.
timer | the timer instance |
alarm_num | the alarm number |
bool timer_hardware_alarm_is_claimed | ( | timer_hw_t * | timer, |
uint | alarm_num | ||
) |
Determine if a hardware alarm has been claimed on the given timer instance.
timer | the timer instance |
alarm_num | the hardware alarm number |
void timer_hardware_alarm_set_callback | ( | timer_hw_t * | timer, |
uint | alarm_num, | ||
hardware_alarm_callback_t | callback | ||
) |
Enable/Disable a callback for a hardware alarm for a given timer instance on this core.
This method enables/disables the alarm IRQ for the specified hardware alarm on the calling core, and set the specified callback to be associated with that alarm.
This callback will be used for the timeout set via hardware_alarm_set_target
timer | the timer instance |
alarm_num | the hardware alarm number |
callback | the callback to install, or NULL to unset |
bool timer_hardware_alarm_set_target | ( | timer_hw_t * | timer, |
uint | alarm_num, | ||
absolute_time_t | t | ||
) |
Set the current target for a specific hardware alarm on the given timer instance.
This will replace any existing target
timer | the timer instance |
alarm_num | the hardware alarm number |
t | the target timestamp |
void timer_hardware_alarm_unclaim | ( | timer_hw_t * | timer, |
uint | alarm_num | ||
) |
cooperatively release the claim on use of this hardware alarm_num on the given timer instance
timer | the timer instance |
alarm_num | the hardware alarm to unclaim |
|
inlinestatic |
Check if the specified timestamp has been reached on the given timer instance.
timer | the timer instance |
t | Absolute time to compare against current time |
|
inlinestatic |
Return a 32 bit timestamp value in microseconds for a given timer instance.
Returns the low 32 bits of the hardware timer.
timer | the timer instance |
uint64_t timer_time_us_64 | ( | timer_hw_t * | timer | ) |
Return the current 64 bit timestamp value in microseconds for a given timer instance.
Returns the full 64 bits of the hardware timer. The pico_time and other functions rely on the fact that this value monotonically increases from power up. As such it is expected that this value counts upwards and never wraps (we apologize for introducing a potential year 5851444 bug).
timer | the timer instance |
Return the current 64 bit timestamp value in microseconds for a given timer instance.