Functions for simulating RP2350 SRAM access from PIO programs. More...

Functions
EPIO_EXPORT uint8_t *	epio_get_sram_ptr (epio_t *epio)
	Get a direct pointer to the emulated SRAM buffer.

EPIO_EXPORT uint8_t	epio_sram_read_byte (epio_t *epio, uint32_t addr)
	Read a byte from the emulated SRAM.

EPIO_EXPORT void	epio_sram_set (epio_t epio, uint32_t addr, uint8_t data, size_t len)
	Write a block of data into the emulated SRAM.

EPIO_EXPORT uint16_t	epio_sram_read_halfword (epio_t *epio, uint32_t addr)
	Read a halfword (16-bit) from the emulated SRAM.

EPIO_EXPORT uint32_t	epio_sram_read_word (epio_t *epio, uint32_t addr)
	Read a word (32-bit) from the emulated SRAM.

EPIO_EXPORT void	epio_sram_write_byte (epio_t *epio, uint32_t addr, uint8_t value)
	Write a byte to the emulated SRAM.

EPIO_EXPORT void	epio_sram_write_halfword (epio_t *epio, uint32_t addr, uint16_t value)
	Write a halfword (16-bit) to the emulated SRAM.

EPIO_EXPORT void	epio_sram_write_word (epio_t *epio, uint32_t addr, uint32_t value)
	Write a word (32-bit) to the emulated SRAM.

Detailed Description

Functions for simulating RP2350 SRAM access from PIO programs.

These functions allow tests to set up and inspect SRAM contents, simulating the RP2350 memory map for PIO programs that read or write SRAM via DMA or direct addressing.

Function Documentation

◆ epio_get_sram_ptr()

EPIO_EXPORT uint8_t * epio_get_sram_ptr ( epio_t * epio )

Get a direct pointer to the emulated SRAM buffer.

Returns the raw backing buffer for epio's emulated SRAM. The returned pointer is valid for the lifetime of the epio instance; address addr in the RP2350 memory map corresponds to offset (addr - MIN_SRAM_ADDR) in this buffer.

The primary use is to unify the firmware's sram_to_host() backing store with epio's SRAM after calling epio_from_apio(), so that subsequent firmware SRAM writes land directly in the running simulation without any explicit syncing step.

Parameters

epio	The epio instance. Must not be NULL.

Returns: Pointer to the internal SRAM buffer; never NULL for a valid instance.

See also: epio_sram_set(), epio_sram_read_byte()

◆ epio_sram_read_byte()

EPIO_EXPORT uint8_t epio_sram_read_byte	(	epio_t *	epio,
		uint32_t	addr
	)

Read a byte from the emulated SRAM.

Parameters

epio	The epio instance.
addr	SRAM address to read.

Returns: The byte value at addr.

◆ epio_sram_read_halfword()

EPIO_EXPORT uint16_t epio_sram_read_halfword	(	epio_t *	epio,
		uint32_t	addr
	)

Read a halfword (16-bit) from the emulated SRAM.

Parameters

epio	The epio instance.
addr	SRAM address to read. Must be 2-byte aligned.

Returns: The 16-bit value at addr.

◆ epio_sram_read_word()

EPIO_EXPORT uint32_t epio_sram_read_word	(	epio_t *	epio,
		uint32_t	addr
	)

Read a word (32-bit) from the emulated SRAM.

Parameters

epio	The epio instance.
addr	SRAM address to read. Must be 4-byte aligned.

Returns: The 32-bit value at addr.

◆ epio_sram_set()

EPIO_EXPORT void epio_sram_set	(	epio_t *	epio,
		uint32_t	addr,
		uint8_t *	data,
		size_t	len
	)

Write a block of data into the emulated SRAM.

Copies len bytes from data into the emulated SRAM starting at addr. Use this to pre-populate SRAM with test data before execution.

Parameters

epio	The epio instance.
addr	Starting SRAM address.
data	Pointer to source data.
len	Number of bytes to write.

◆ epio_sram_write_byte()

EPIO_EXPORT void epio_sram_write_byte	(	epio_t *	epio,
		uint32_t	addr,
		uint8_t	value
	)

Write a byte to the emulated SRAM.

Parameters

epio	The epio instance.
addr	SRAM address to write.
value	The byte value to write.

◆ epio_sram_write_halfword()

EPIO_EXPORT void epio_sram_write_halfword	(	epio_t *	epio,
		uint32_t	addr,
		uint16_t	value
	)

Write a halfword (16-bit) to the emulated SRAM.

Parameters

epio	The epio instance.
addr	SRAM address to write. Must be 2-byte aligned.
value	The 16-bit value to write.

◆ epio_sram_write_word()

EPIO_EXPORT void epio_sram_write_word	(	epio_t *	epio,
		uint32_t	addr,
		uint32_t	value
	)

Write a word (32-bit) to the emulated SRAM.

Parameters

epio	The epio instance.
addr	SRAM address to write. Must be 4-byte aligned.
value	The 32-bit value to write.