ssr.h File Reference

This file contains functions to conveniently program Snitch's SSRs. More...

Go to the source code of this file.

Enumerations
enum	snrt_ssr_dm { SNRT_SSR_DM0 = 0 , SNRT_SSR_DM1 = 1 , SNRT_SSR_DM2 = 2 , SNRT_SSR_DM_ALL = 31 }
	The different SSRs. More...
enum	snrt_ssr_dim { SNRT_SSR_1D = 0 , SNRT_SSR_2D = 1 , SNRT_SSR_3D = 2 , SNRT_SSR_4D = 3 }
	The different dimensions. More...
enum	{   REG_STATUS = 0 , REG_REPEAT = 1 , REG_BOUNDS = 2 , REG_STRIDES = 6 ,   REG_RPTR = 24 , REG_WPTR = 28 }
	The SSR configuration registers. More...

Functions
void	snrt_fpu_fence ()
	Synchronize the integer and float pipelines.
void	snrt_ssr_enable ()
	Enable all SSRs.
void	snrt_ssr_disable ()
	Disable all SSRs.
uint32_t	read_ssr_cfg (uint32_t reg, uint32_t dm)
	Read the value of an SSR configuration register.
void	write_ssr_cfg (uint32_t reg, uint32_t dm, uint32_t value)
	Write a value to an SSR configuration register.
void	snrt_ssr_loop_1d (enum snrt_ssr_dm dm, size_t b0, size_t s0)
	Configure an SSR data mover for a 1D loop nest.
void	snrt_ssr_loop_2d (enum snrt_ssr_dm dm, size_t b0, size_t b1, size_t s0, size_t s1)
	Configure an SSR data mover for a 2D loop nest.
void	snrt_ssr_loop_3d (enum snrt_ssr_dm dm, size_t b0, size_t b1, size_t b2, size_t s0, size_t s1, size_t s2)
	Configure an SSR data mover for a 3D loop nest.
void	snrt_ssr_loop_4d (enum snrt_ssr_dm dm, size_t b0, size_t b1, size_t b2, size_t b3, size_t s0, size_t s1, size_t s2, size_t s3)
	Configure an SSR data mover for a 4D loop nest.
void	snrt_ssr_repeat (enum snrt_ssr_dm dm, size_t count)
	Configure the repetition count for a stream.
void	snrt_ssr_read (enum snrt_ssr_dm dm, enum snrt_ssr_dim dim, volatile void *ptr)
	Start a streaming read.
void	snrt_ssr_write (enum snrt_ssr_dm dm, enum snrt_ssr_dim dim, volatile void *ptr)
	Start a streaming write.

Detailed Description

This file contains functions to conveniently program Snitch's SSRs.

An SSR stream can be configured to replace a store (or load) sequence as could be generated by an N-dimensional affine loop nest:

for (int i = 0; i < b1; i++)
    for (int j = 0; j < b0; j++)
        array[i * s1 + j * s0] = 0;

The configuration functions provided in this file reflect the parameters one would define to set up such a loop nest.

Enumeration Type Documentation

anonymous enum

anonymous enum

The SSR configuration registers.

Enumerator
REG_STATUS	SSR status register
REG_REPEAT	SSR repeat register
REG_BOUNDS	SSR bounds register
REG_STRIDES	SSR strides register
REG_RPTR	SSR read pointer register
REG_WPTR	SSR write pointer register

snrt_ssr_dim

enum snrt_ssr_dim

The different dimensions.

Enumerator
SNRT_SSR_1D	1D stream
SNRT_SSR_2D	2D stream
SNRT_SSR_3D	3D stream
SNRT_SSR_4D	4D stream

snrt_ssr_dm

enum snrt_ssr_dm

The different SSRs.

Enumerator
SNRT_SSR_DM0	SSR data mover 0
SNRT_SSR_DM1	SSR data mover 1
SNRT_SSR_DM2	SSR data mover 2
SNRT_SSR_DM_ALL	Write to all SSRs

Function Documentation

read_ssr_cfg()

uint32_t read_ssr_cfg ( uint32_t reg, uint32_t dm )

inline

Read the value of an SSR configuration register.

Parameters

reg	The register index.
dm	The SSR index.

Returns

The value of the register.

snrt_ssr_loop_1d()

void snrt_ssr_loop_1d ( enum snrt_ssr_dm dm, size_t b0, size_t s0 )

inline

Configure an SSR data mover for a 1D loop nest.

Parameters

dm	The SSR index.
b0	The bound of the loop.
s0	The stride of the loop.

snrt_ssr_loop_2d()

void snrt_ssr_loop_2d ( enum snrt_ssr_dm dm, size_t b0, size_t b1, size_t s0, size_t s1 )

inline

Configure an SSR data mover for a 2D loop nest.

Parameters

dm	The SSR index.
b0	The bound of the first loop.
b1	The bound of the second loop.
s0	The stride of the first loop.
s1	The stride of the second loop.

snrt_ssr_loop_3d()

void snrt_ssr_loop_3d ( enum snrt_ssr_dm dm, size_t b0, size_t b1, size_t b2, size_t s0, size_t s1, size_t s2 )

inline

Configure an SSR data mover for a 3D loop nest.

Parameters

dm	The SSR index.
b0	The bound of the first loop.
b1	The bound of the second loop.
b2	The bound of the third loop.
s0	The stride of the first loop.
s1	The stride of the second loop.
s2	The stride of the third loop.

snrt_ssr_loop_4d()

void snrt_ssr_loop_4d ( enum snrt_ssr_dm dm, size_t b0, size_t b1, size_t b2, size_t b3, size_t s0, size_t s1, size_t s2, size_t s3 )

inline

Configure an SSR data mover for a 4D loop nest.

Parameters

dm	The SSR index.
b0	The bound of the first loop.
b1	The bound of the second loop.
b2	The bound of the third loop.
b3	The bound of the fourth loop.
s0	The stride of the first loop.
s1	The stride of the second loop.
s2	The stride of the third loop.
s3	The stride of the fourth loop.

snrt_ssr_read()

void snrt_ssr_read ( enum snrt_ssr_dm dm, enum snrt_ssr_dim dim, volatile void * ptr )

inline

Start a streaming read.

Parameters

dm	The SSR index.
dim	The number of dimensions to use.
ptr	The pointer to the data.

snrt_ssr_repeat()

void snrt_ssr_repeat ( enum snrt_ssr_dm dm, size_t count )

inline

Configure the repetition count for a stream.

Parameters

dm	The SSR index.
count	The repetition count.

snrt_ssr_write()

void snrt_ssr_write ( enum snrt_ssr_dm dm, enum snrt_ssr_dim dim, volatile void * ptr )

inline

Start a streaming write.

Parameters

dm	The SSR index.
dim	The number of dimensions to use.
ptr	The pointer to the data.

write_ssr_cfg()

void write_ssr_cfg ( uint32_t reg, uint32_t dm, uint32_t value )

inline

Write a value to an SSR configuration register.

Parameters

reg	The register index.
dm	The SSR index.
value	The value to write.