IRAM Precache Support

Collaboration diagram for IRAM Precache Support:

Macros
#define	IRAM_PRECACHE_ATTR
#define	IRAM_PRECACHE_START(tag)
#define	IRAM_PRECACHE_END(tag)
#define	IRAM_PRECACHE_ATTR   __attribute__((optimize("no-reorder-blocks"))) __attribute__((noinline))
	Tools for pre-loading code into the flash cache. More...
#define	IRAM_PRECACHE_START(tag)
	Place this macro before the first line of the critical code. More...
#define	IRAM_PRECACHE_END(tag)   iram_precache_end_##tag:
	Place this macro after the last line of critical code. More...
#define	IRAM_PRECACHE_ATTR
#define	IRAM_PRECACHE_START(tag)
#define	IRAM_PRECACHE_END(tag)

Functions
void	iram_precache (void *addr, uint32_t bytes)
	Pre-load flash data into the flash instruction cache. More...

Detailed Description

Macro Definition Documentation

IRAM_PRECACHE_ATTR [1/3]

#define IRAM_PRECACHE_ATTR

IRAM_PRECACHE_ATTR [2/3]

#define IRAM_PRECACHE_ATTR   __attribute__((optimize("no-reorder-blocks"))) __attribute__((noinline))

Tools for pre-loading code into the flash cache.

• It can be useful for code that accesses/uses SPI0 which is connected to the flash chip.
• Non interrupt handler code that is infrequently called but might otherwise require being in valuable IRAM - such as bit-banging I/O code or some code run at bootup can avoid being permanently in IRAM.

Mark functions containing critical code using this attribute

IRAM_PRECACHE_ATTR [3/3]

#define IRAM_PRECACHE_ATTR

IRAM_PRECACHE_END [1/3]

#define IRAM_PRECACHE_END

(

tag

)

IRAM_PRECACHE_END [2/3]

#define IRAM_PRECACHE_END

(

tag

)

iram_precache_end_##tag:

Place this macro after the last line of critical code.

Parameters

tag	Must be the same tag used in IRAM_PRECACHE_START()

IRAM_PRECACHE_END [3/3]

#define IRAM_PRECACHE_END

(

tag

)

IRAM_PRECACHE_START [1/3]

#define IRAM_PRECACHE_START

(

tag

)

IRAM_PRECACHE_START [2/3]

#define IRAM_PRECACHE_START

(

tag

)

Value:

    iram_precache(NULL, (uint8_t*)&&iram_precache_end_##tag - (uint8_t*)&&iram_precache_start_##tag);                  \
    iram_precache_start_##tag:

Place this macro before the first line of the critical code.

Parameters

tag	Used to create the precached section name, must be globally unique

Note

Do not omit the tag, and be careful with naming to avoid conflicts

IRAM_PRECACHE_START [3/3]

#define IRAM_PRECACHE_START

(

tag

)

Function Documentation

iram_precache()

void iram_precache	(	void *	addr,
		uint32_t	bytes
	)

Pre-load flash data into the flash instruction cache.

Parameters

addr	First location to cache, specify NULL to use current location.
bytes	Number of bytes to cache

Note

All pages containing the requested region will be read to pull them into cache RAM.