PMU Functions for Armv8.1-M

Functions that relate to the Performance Monitoring Unit. More...

Content
	PMU Events for Armv8.1-M
	IDs for Armv8.1-M architecture defined events.
	PMU Events for Cortex-M55
	IDs for additional events defined for Cortex-M55.
	PMU Events for Cortex-M85
	IDs for additional events defined for Cortex-M85.

Data Structures
struct	PMU_Type
	Structure type to access the Performance Monitoring Unit (PMU). More...

Macros
#define	PMU
	PMU configuration struct.

Functions
__STATIC_INLINE void	ARM_PMU_CNTR_Disable (uint32_t mask)
	Disable counters.
__STATIC_INLINE void	ARM_PMU_CNTR_Enable (uint32_t mask)
	Enable counters.
__STATIC_INLINE void	ARM_PMU_CNTR_Increment (uint32_t mask)
	Software increment event counter.
__STATIC_INLINE void	ARM_PMU_CYCCNT_Reset (void)
	Reset cycle counter.
__STATIC_INLINE void	ARM_PMU_Disable (void)
	Disable the PMU.
__STATIC_INLINE void	ARM_PMU_Enable (void)
	Enable the PMU.
__STATIC_INLINE void	ARM_PMU_EVCNTR_ALL_Reset (void)
	Reset all event counters.
__STATIC_INLINE uint32_t	ARM_PMU_Get_CCNTR (void)
	Read cycle counter.
__STATIC_INLINE uint32_t	ARM_PMU_Get_CNTR_OVS (void)
	Read counter overflow status.
__STATIC_INLINE uint32_t	ARM_PMU_Get_EVCNTR (uint32_t num)
	Read event counter.
__STATIC_INLINE void	ARM_PMU_Set_CNTR_IRQ_Disable (uint32_t mask)
	Disable counter overflow interrupt request.
__STATIC_INLINE void	ARM_PMU_Set_CNTR_IRQ_Enable (uint32_t mask)
	Enable counter overflow interrupt request.
__STATIC_INLINE void	ARM_PMU_Set_CNTR_OVS (uint32_t mask)
	Clear counter overflow status.
__STATIC_INLINE void	ARM_PMU_Set_EVTYPER (uint32_t num, uint32_t type)
	Set event to count for PMU event counter.

Description

Functions that relate to the Performance Monitoring Unit.

The following functions support the Performance Monitoring Unit (PMU) that is available on the Cortex-M55/M85 processors.

The PMU is used to monitor events that occur during run-time of an application.

Example:

// Initialize counter variables
 
unsigned int cycle_count = 0;
unsigned int l1_dcache_miss_count = 0;
unsigned int instructions_retired_count = 0;
 
// Enable the PMU
// Note: Before using the PMU, software needs to ensure 
// that trace is enabled via the Debug Exception Monitor Control Register, DEMCR:
// CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
 
ARM_PMU_Enable();
 
// Configure Event Counter Register 0 to count instructions retired
// Configure Event Counter Register 1 to count L1 D-Cache misses
 
ARM_PMU_Set_EVTYPER(0, ARM_PMU_INST_RETIRED);
ARM_PMU_Set_EVTYPER(1, ARM_PMU_L1D_CACHE_MISS_RD);
 
// Reset Event Counters and Cycle Counter
 
ARM_PMU_EVCNTR_ALL_Reset();
ARM_PMU_CYCCNT_Reset();
 
// Start incrementing Cycle Count Register and Event Counter Registers 0 & 1
 
ARM_PMU_CNTR_Enable(PMU_CNTENSET_CCNTR_ENABLE_Msk|PMU_CNTENSET_CNT0_ENABLE_Msk|PMU_CNTENSET_CNT1_ENABLE_Msk);
 
// Code you want to measure here
 
// Stop incrementing Cycle Count Register and Event Counter Registers 0 & 1
 
ARM_PMU_CNTR_Disable(PMU_CNTENCLR_CCNTR_ENABLE_Msk|PMU_CNTENCLR_CNT0_ENABLE_Msk|PMU_CNTENCLR_CNT1_ENABLE_Msk);
 
// Get cycle count, number of instructions retired and number of L1 D-Cache misses (on read)
 
cycle_count = cycle_count + ARM_PMU_Get_CCNTR();
instructions_retired_count = instructions_retired_count + ARM_PMU_Get_EVCNTR(0);
l1_dcache_miss_count = l1_dcache_miss_count + ARM_PMU_Get_EVCNTR(1);      // Note: D-Cache must be enabled using
                                                                          // SCB_EnableDCache() for meaningful result.

Macro Definition Documentation

PMU

#define PMU

PMU configuration struct.

This macro can be used to access the PMU registers, directly. For the common tasks one should prefer using the control functions.

Example: Example:

PMU->CTRL |= PMU_CTRL_ENABLE_Msk; // Enable PMU

Function Documentation

ARM_PMU_CNTR_Disable()

__STATIC_INLINE void ARM_PMU_CNTR_Disable

(

uint32_t

mask

)

Disable counters.

Parameters

[in]

mask

Counters to enable

Note

Disables one or more of the following:

• event counters (0-30)
• cycle counter

ARM_PMU_CNTR_Enable()

__STATIC_INLINE void ARM_PMU_CNTR_Enable

(

uint32_t

mask

)

Enable counters.

Parameters

[in]

mask

Counters to enable

Note

Enables one or more of the following:

• event counters (0-30)
• cycle counter

ARM_PMU_CNTR_Increment()

__STATIC_INLINE void ARM_PMU_CNTR_Increment

(

uint32_t

mask

)

Software increment event counter.

Parameters

[in]

mask

Counters to increment

Note

Software increment bits for one or more event counters (0-30)

ARM_PMU_CYCCNT_Reset()

__STATIC_INLINE void ARM_PMU_CYCCNT_Reset

(

void

)

Reset cycle counter.

ARM_PMU_Disable()

__STATIC_INLINE void ARM_PMU_Disable

(

void

)

Disable the PMU.

ARM_PMU_Enable()

__STATIC_INLINE void ARM_PMU_Enable

(

void

)

Enable the PMU.

ARM_PMU_EVCNTR_ALL_Reset()

__STATIC_INLINE void ARM_PMU_EVCNTR_ALL_Reset

(

void

)

Reset all event counters.

ARM_PMU_Get_CCNTR()

__STATIC_INLINE uint32_t ARM_PMU_Get_CCNTR

(

void

)

Read cycle counter.

Returns

Cycle count

ARM_PMU_Get_CNTR_OVS()

__STATIC_INLINE uint32_t ARM_PMU_Get_CNTR_OVS

(

void

)

Read counter overflow status.

Returns

Counter overflow status bits for the following:

• event counters (0-30)
• cycle counter

ARM_PMU_Get_EVCNTR()

__STATIC_INLINE uint32_t ARM_PMU_Get_EVCNTR

(

uint32_t

num

)

Read event counter.

Parameters

[in]

num

Event counter (0-30) to read

Returns

Event count

ARM_PMU_Set_CNTR_IRQ_Disable()

__STATIC_INLINE void ARM_PMU_Set_CNTR_IRQ_Disable

(

uint32_t

mask

)

Disable counter overflow interrupt request.

Parameters

[in]

mask

Counter overflow interrupt request bits to clear

Note

Clears overflow interrupt request bits for one or more of the following:

• event counters (0-30)
• cycle counter

ARM_PMU_Set_CNTR_IRQ_Enable()

__STATIC_INLINE void ARM_PMU_Set_CNTR_IRQ_Enable

(

uint32_t

mask

)

Enable counter overflow interrupt request.

Parameters

[in]

mask

Counter overflow interrupt request bits to set

Note

Sets overflow interrupt request bits for one or more of the following:

• event counters (0-30)
• cycle counter

ARM_PMU_Set_CNTR_OVS()

__STATIC_INLINE void ARM_PMU_Set_CNTR_OVS

(

uint32_t

mask

)

Clear counter overflow status.

Parameters

[in]

mask

Counter overflow status bits to clear

Note

Clears overflow status bits for one or more of the following:

• event counters (0-30)
• cycle counter

ARM_PMU_Set_EVTYPER()

__STATIC_INLINE void ARM_PMU_Set_EVTYPER	(	uint32_t	num,
		uint32_t	type
	)

Set event to count for PMU event counter.

Parameters

[in]	num	Event counter (0-30) to configure
[in]	type	Event to count