neorv32_cpu.h File Reference

CPU Core Functions HW driver header file. More...

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Functions
void	__neorv32_crt0_after_main (int32_t return_code)
void	neorv32_cpu_store_unsigned_word (uint32_t addr, uint32_t wdata)
void	neorv32_cpu_store_unsigned_half (uint32_t addr, uint16_t wdata)
void	neorv32_cpu_store_unsigned_byte (uint32_t addr, uint8_t wdata)
uint32_t	neorv32_cpu_load_unsigned_word (uint32_t addr)
uint16_t	neorv32_cpu_load_unsigned_half (uint32_t addr)
int16_t	neorv32_cpu_load_signed_half (uint32_t addr)
uint8_t	neorv32_cpu_load_unsigned_byte (uint32_t addr)
int8_t	neorv32_cpu_load_signed_byte (uint32_t addr)
uint32_t	neorv32_cpu_csr_read (const int csr_id)
void	neorv32_cpu_csr_write (const int csr_id, uint32_t data)
void	neorv32_cpu_csr_set (const int csr_id, uint32_t mask)
void	neorv32_cpu_csr_clr (const int csr_id, uint32_t mask)
void	neorv32_cpu_sleep (void)
Prototypes
void	neorv32_cpu_irq_enable (int irq_sel)
void	neorv32_cpu_irq_disable (int irq_sel)
uint64_t	neorv32_cpu_get_cycle (void)
void	neorv32_cpu_set_mcycle (uint64_t value)
uint64_t	neorv32_cpu_get_instret (void)
void	neorv32_cpu_set_minstret (uint64_t value)
void	neorv32_cpu_delay_ms (uint32_t time_ms)
uint32_t	neorv32_cpu_get_clk_from_prsc (int prsc)
uint32_t	neorv32_cpu_pmp_get_num_regions (void)
uint32_t	neorv32_cpu_pmp_get_granularity (void)
int	neorv32_cpu_pmp_configure_region (int index, uint32_t addr, uint8_t config)
uint32_t	neorv32_cpu_hpm_get_num_counters (void)
uint32_t	neorv32_cpu_hpm_get_size (void)
void	neorv32_cpu_goto_user_mode (void)

Detailed Description

CPU Core Functions HW driver header file.

Function Documentation

__neorv32_crt0_after_main()

void __neorv32_crt0_after_main

(

int32_t

return_code

)

Prototype for "after-main handler". This function is called if main() returns.

Parameters

[in]

return_code

Return value of main() function.

"after-main" handler that is executed after the application's main function returns (called by crt0.S start-up code)

"after-main" handler that is executed after the application's main function returns (called by crt0.S start-up code): Output minimal test report to physical UART

neorv32_cpu_csr_clr()

void neorv32_cpu_csr_clr ( const int  csr_id, uint32_t  mask  )

inline

Clear bit(s) in CPU control and status register (CSR).

Parameters

[in]	csr_id	ID of CSR to write. See NEORV32_CSR_enum.
[in]	mask	Bit mask (high-active) to clear bits (uint32_t).

neorv32_cpu_csr_read()

uint32_t neorv32_cpu_csr_read ( const int  csr_id )

inline

Read data from CPU control and status register (CSR).

Parameters

[in]

csr_id

ID of CSR to read. See NEORV32_CSR_enum.

Returns

Read data (uint32_t).

neorv32_cpu_csr_set()

void neorv32_cpu_csr_set ( const int  csr_id, uint32_t  mask  )

inline

Set bit(s) in CPU control and status register (CSR).

Parameters

[in]	csr_id	ID of CSR to write. See NEORV32_CSR_enum.
[in]	mask	Bit mask (high-active) to set bits (uint32_t).

neorv32_cpu_csr_write()

void neorv32_cpu_csr_write ( const int  csr_id, uint32_t  data  )

inline

Write data to CPU control and status register (CSR).

Parameters

[in]	csr_id	ID of CSR to write. See NEORV32_CSR_enum.
[in]	data	Data to write (uint32_t).

neorv32_cpu_delay_ms()

void neorv32_cpu_delay_ms

(

uint32_t

time_ms

)

Delay function using busy wait.

Note

This function uses the cycle CPU counter if available. Otherwise the MTIME system timer is used if available. A simple loop is used as alternative fall-back (imprecise!).

Parameters

[in]

time_ms

Time in ms to wait (unsigned 32-bit).

neorv32_cpu_get_clk_from_prsc()

uint32_t neorv32_cpu_get_clk_from_prsc

(

int

prsc

)

Get actual clocking frequency from prescaler select NEORV32_CLOCK_PRSC_enum

Parameters

[in]

prsc

Prescaler select NEORV32_CLOCK_PRSC_enum. return Actual raw clock frequency in Hz.

neorv32_cpu_get_cycle()

uint64_t neorv32_cpu_get_cycle

(

void

)

Get cycle counter from cycle[h].

Returns

Current cycle counter (64 bit).

neorv32_cpu_get_instret()

uint64_t neorv32_cpu_get_instret

(

void

)

Get retired instructions counter from instret[h].

Returns

Current instructions counter (64 bit).

neorv32_cpu_goto_user_mode()

void neorv32_cpu_goto_user_mode

(

void

)

Switch from privilege mode MACHINE to privilege mode USER.

Note

This function will return with the CPU being in user mode.

neorv32_cpu_hpm_get_num_counters()

uint32_t neorv32_cpu_hpm_get_num_counters

(

void

)

Hardware performance monitors (HPM): Get number of available HPM counters.

Returns

Returns number of available HPM counters (0..29).

neorv32_cpu_hpm_get_size()

uint32_t neorv32_cpu_hpm_get_size

(

void

)

Hardware performance monitors (HPM): Get total counter width

Warning

This function overrides the mhpmcounter3[h] CSRs.

Returns

Size of HPM counters (1-64, 0 if not implemented at all).

neorv32_cpu_irq_disable()

void neorv32_cpu_irq_disable

(

int

irq_sel

)

Disable specific interrupt channel.

Note

This functions also tries to clear the pending flag of the interrupt.

Parameters

[in]

irq_sel

CPU interrupt select. See NEORV32_CSR_MIE_enum.

neorv32_cpu_irq_enable()

void neorv32_cpu_irq_enable

(

int

irq_sel

)

Unavailable extensions warning. Enable specific interrupt channel.

Note

This functions also tries to clear the pending flag of the interrupt.

Parameters

[in]

irq_sel

CPU interrupt select. See NEORV32_CSR_MIE_enum.

neorv32_cpu_load_signed_byte()

int8_t neorv32_cpu_load_signed_byte ( uint32_t  addr )

inline

Load signed byte from address space.

Parameters

[in]

addr

Address (32-bit).

Returns

Read data byte (8-bit).

neorv32_cpu_load_signed_half()

int16_t neorv32_cpu_load_signed_half ( uint32_t  addr )

inline

Load signed half-word from address space.

Note

An unaligned access address will raise an alignment exception.

Parameters

[in]

addr

Address (32-bit).

Returns

Read data half-word (16-bit).

neorv32_cpu_load_unsigned_byte()

uint8_t neorv32_cpu_load_unsigned_byte ( uint32_t  addr )

inline

Load unsigned byte from address space.

Parameters

[in]

addr

Address (32-bit).

Returns

Read data byte (8-bit).

neorv32_cpu_load_unsigned_half()

uint16_t neorv32_cpu_load_unsigned_half ( uint32_t  addr )

inline

Load unsigned half-word from address space.

Note

An unaligned access address will raise an alignment exception.

Parameters

[in]

addr

Address (32-bit).

Returns

Read data half-word (16-bit).

neorv32_cpu_load_unsigned_word()

uint32_t neorv32_cpu_load_unsigned_word ( uint32_t  addr )

inline

Load unsigned word from address space.

Note

An unaligned access address will raise an alignment exception.

Parameters

[in]

addr

Address (32-bit).

Returns

Read data word (32-bit).

neorv32_cpu_pmp_configure_region()

int neorv32_cpu_pmp_configure_region	(	int	index,
		uint32_t	addr,
		uint8_t	config
	)

Physical memory protection (PMP): Configure region.

Note

This function requires the PMP CPU extension.

Warning

This function expects a WORD address!

Parameters

[in]	index	Region number (index, 0..PMP_NUM_REGIONS-1).
[in]	addr	Region address (word address!).
[in]	config	Region configuration byte (see NEORV32_PMPCFG_ATTRIBUTES_enum).

Returns

Returns 0 on success, !=0 on failure.

neorv32_cpu_pmp_get_granularity()

uint32_t neorv32_cpu_pmp_get_granularity

(

void

)

Physical memory protection (PMP): Get minimal region size (granularity).

Warning

This function overrides PMPCFG0[0] and PMPADDR0 CSRs!

Note

This function requires the PMP CPU extension.

Returns

Returns minimal region size in bytes. Returns zero on error.

neorv32_cpu_pmp_get_num_regions()

uint32_t neorv32_cpu_pmp_get_num_regions

(

void

)

Physical memory protection (PMP): Get number of available regions.

Warning

This function overrides all available PMPCFG* CSRs!

Note

This function requires the PMP CPU extension.

Returns

Returns number of available PMP regions.

neorv32_cpu_set_mcycle()

void neorv32_cpu_set_mcycle

(

uint64_t

value

)

Set machine cycle counter mcycle[h].

Parameters

[in]

value

New value for mcycle[h] CSR (64-bit).

neorv32_cpu_set_minstret()

void neorv32_cpu_set_minstret

(

uint64_t

value

)

Set machine retired instructions counter minstret[h].

Parameters

[in]

value

New value for mcycle[h] CSR (64-bit).

neorv32_cpu_sleep()

void neorv32_cpu_sleep ( void  )

inline

Put CPU into "sleep" mode.

Note

This function executes the WFI instruction. The WFI (wait for interrupt) instruction will make the CPU stall until an interrupt request is detected. Interrupts have to be globally enabled and at least one external source must be enabled (like the MTI machine timer interrupt) to allow the CPU to wake up again. If 'Zicsr' CPU extension is disabled, this will permanently stall the CPU.

neorv32_cpu_store_unsigned_byte()

void neorv32_cpu_store_unsigned_byte ( uint32_t  addr, uint8_t  wdata  )

inline

Store unsigned byte to address space.

Parameters

[in]	addr	Address (32-bit).
[in]	wdata	Data byte (8-bit) to store.

neorv32_cpu_store_unsigned_half()

void neorv32_cpu_store_unsigned_half ( uint32_t  addr, uint16_t  wdata  )

inline

Store unsigned half-word to address space.

Note

An unaligned access address will raise an alignment exception.

Parameters

[in]	addr	Address (32-bit).
[in]	wdata	Data half-word (16-bit) to store.

neorv32_cpu_store_unsigned_word()

void neorv32_cpu_store_unsigned_word ( uint32_t  addr, uint32_t  wdata  )

inline

Store unsigned word to address space.

Note

An unaligned access address will raise an alignment exception.

Parameters

[in]	addr	Address (32-bit).
[in]	wdata	Data word (32-bit) to store.