xcore/sc_sdcard

SD-card component

SD Card Libary

Stable release:	1.0.1
Status:	alpha
Maintainer:	interactive_matter
Description:	SD card driver library

Key Features

• Read and write data operations on SD cards using either the SPI interface or native 4bit interface
• Port of FatFS - FAT file system module R0.09 (C)ChaN, 2011 (http://elm-chan.org/fsw/ff/00index_e.html).
• Beware: FAT with long file names may be covered by various patents (in particular those held by Microsoft). Use of this code may require licensing from the patent holders
• Beware: 4bit SD protocol is subject to petents of the SD Association. When enabled on commercial products a license may be required. (see: https://www.sdcard.org/developers/howto/ )
• Benchmark with 4bit interface multiblock read speed is about 4MBytes/sec. 1.2MBytes/sec with SPI.

To Do

• Initialization at low clock speed (400KHz max) for the 4bit interface.
• Test with SDXC card, SD physical layer ver 1.0 compliant card and MMC card (currently supported only with SPI interface).
• support for MMC/eMMC at 4 and 8bit bus.
• Date/Time function for files timestamp returning real date/time.

Firmware Overview

This module provides functions to initialize SD cards, read and write data. To enable the 4bit SD native bus interface functions it is necessary to uncomment the "//#define BUS_MODE_4BIT" in the "module_FatFs/src/diskio.h". Resources (ports and clock blocks) used for the interface need to be specified in either "module_sdcardSPI/SDCardHostSPI.xc" or "module_sdcard4bit/SDCardHost4bit.xc" in the initialization of the SDif structure. If you run it in a core other than XS1_G you need pull-up resistor for miso line (if in spi mode) or Cmd line and D0(=Dat port bit 3) line (if in 4bit bus mode)

Known Issues

• Initialization for the 4bit protocol not done at correct clock speed of 400KHz maximum.

Required Repositories

• xcommon [email protected]:xcore/xcommon.git

Support

Issues may be submitted via the Issues tab in this github repo. Response to any issues submitted are at the discretion of the maintainers of this component.

sc_sdcard's Issues

Can't read data from memory card.

Hello !!!
I tried to interface with a memory card but could not get it.
I am using SanDisk ultra sd card with the adapter because you can't directly connect on it.
My pin connections should be,

Pin1 (CS ) ----> P1L
Pin2 (MOSI[DI]) ---> P1K
Pin3 (GND) ---> GND
Pin4 (3V) ---> 3V3
Pin5 (CLK) ---> P1I
Pin6 (GND) ---> GND
Pin7 (MISO[DO]) ---> P1J
Pin8 (NC) --->NC
Pin9 (NC) --->NC

I tried to place 10k pull up on pin2[MOSI] and pin7[MISO]. Still do not get any response.

I tested the same thing Arduino sd card module it works well.

In SDCardHostSPI.xc,

static SDHostInterface SDif[] = // LIST HERE THE PORTS USED FOR THE INTERFACES
// cs, sclk, Mosi, miso
{{XS1_CLKBLK_1, XS1_CLKBLK_2, XS1_PORT_1L, XS1_PORT_1I, XS1_PORT_1K, XS1_PORT_1J, 0, 0}}; // resources used for interface #0

changed as per defined output.

I hope anyone helps me get out this problem.

Use of hard coded pull-up is harmful

Both module_sdcard4bit and module_sdcardSPI hard coded enables the internal pull-up resistors on some ports. This will work fine on XS1-G devices that have pull-up resistors, but it will cause an exception on XS1-L devices because they do not have internal pull-up resistors (instead they have pull-down resistors).

Assumptions about the target device cannot be made implicitly. I propose to either fully rely on external pull-up resistors regarding the software or to pass a parameter to an initialization routine that will either do nothing or enable the internal pull-up depending on the value of the parameter.

Check READ results match data written.

The test program currently doesn't check this. I've put an improved version on https://github.com/tuck1s/sc_sdcard

FatFs is an old version

module FatFs is baed on FatFs R0.09. Later versions are now available. It would be good to move up to the latest version,

Exception in f_read() when #define _FS_TINY set to 1

I get a memory exception in f_read() when _FS_TINY is set to 1. Seems to work fine with _FS_TINY set to 0