SDSafeSPI Class Reference

SPI interface routines for SD & SDHC & MMC cards. More...

#include <sdsafespi.h>

Public Member Functions
int	Start (const int basepin)
	Start a new cog with the SPI driver. More...
int	Start (const int pin_do, const int pin_clk, const int pin_di, const int pin_cs)
	Start a new cog with the SPI driver. More...
void	ReadBlock (const int block_index, char *buffer_address)
void	WriteBlock (const int block_index, char *buffer_address)
void	ReleaseCard (void)
	Release the SPI bus and allow other devices to use it. More...
void	Stop (void)
	Kill the assembly driver cog. More...
bool	HasError (void) const
	If there was an error in the SD routines then this function will return an error code. More...
void	ClearError (void)
	Resets the error flag to kNoError. More...
int	GetError (void) const

Static Public Attributes
static const int	kCardTypeMMC = 1
static const int	kCardTypeSD = 2
static const int	kCardTypeSDHC = 3
static const int	kNoError = 0
static const int	kErrorCardNotReset = -1
static const int	kError3v3NotSupported = -2
static const int	kErrorOcrFailed = -3
static const int	kErrorBlockNotLongAligned = -4
static const int	kErrorAsmNoReadToken = 100
static const int	kErrorAsmBlockNotWritten = 101
static const int	kErrorSpiEngineNotRunning = -999
static const int	kErrorCardBusyTimeout = -1000

Detailed Description

SPI interface routines for SD & SDHC & MMC cards.

C++ conversion by SRLM, based on sdsafespi.spin version 0.3.0 by Jonathan "lonesock" Dummer.

This uses multiblock SPI mode exclusively.

This is the "SAFE" version...uses

• 1 instruction per bit writes
• 2 instructions per bit reads

Warning

You should check the error code after each function call. Something may have gone wrong, and this is the only way to know! If there is an error, the safest thing to do would be to destroy the object instance, fix the error, and try again. For some errors, it may be ok to simply clear the error and try again.

Notes:

• It appears that negative Spi_command is never used in the assembly code. This looks like an old error possibility that is no longer used. Can we take it out?

Todo:

(SRLM): Convert the SD SPI driver to GAS instead of binary.

Author

SRLM (srlm@.nosp@m.srlm.nosp@m.produ.nosp@m.ctio.nosp@m.ns.co.nosp@m.m)

Member Function Documentation

void SDSafeSPI::ClearError ( void  )

inline

Resets the error flag to kNoError.

int SDSafeSPI::GetError ( void  ) const

inline

bool SDSafeSPI::HasError ( void  ) const

inline

If there was an error in the SD routines then this function will return an error code.

Returns

The error code.

void SDSafeSPI::ReadBlock ( const int  block_index, char *  buffer_address  )

inline

void SDSafeSPI::ReleaseCard ( void  )

inline

Release the SPI bus and allow other devices to use it.

The SPI bus is re-acquired the next time a block is transfered.

Warning

If you release the lines, make sure that the other devices are not using the bus the next time you do an SD operation.

int SDSafeSPI::Start ( const int  basepin)

inline

Start a new cog with the SPI driver.

Warning

requires that the pins be both consecutive, and in the order

1. DO
2. CLK
3. DI
4. CS

Returns

The card type constant.

int SDSafeSPI::Start ( const int  pin_do, const int  pin_clk, const int  pin_di, const int  pin_cs  )

inline

Start a new cog with the SPI driver.

Parameters

pin_do
pin_clk
pin_di
pin_cs

Returns

The card type constant.

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void SDSafeSPI::Stop ( void  )

inline

Kill the assembly driver cog.

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void SDSafeSPI::WriteBlock ( const int  block_index, char *  buffer_address  )

inline

Member Data Documentation

const int SDSafeSPI::kCardTypeMMC = 1

static

const int SDSafeSPI::kCardTypeSD = 2

static

const int SDSafeSPI::kCardTypeSDHC = 3

static

const int SDSafeSPI::kError3v3NotSupported = -2

static

const int SDSafeSPI::kErrorAsmBlockNotWritten = 101

static

const int SDSafeSPI::kErrorAsmNoReadToken = 100

static

const int SDSafeSPI::kErrorBlockNotLongAligned = -4

static

const int SDSafeSPI::kErrorCardBusyTimeout = -1000

static

const int SDSafeSPI::kErrorCardNotReset = -1

static

const int SDSafeSPI::kErrorOcrFailed = -3

static

const int SDSafeSPI::kErrorSpiEngineNotRunning = -999

static

const int SDSafeSPI::kNoError = 0

static

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The documentation for this class was generated from the following file:

• sdsafespi.h