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Programming MicrocontrollerSPP and File system

32K Byte 32K Byte Burst FlashBurst Flash

64K or 96K 64K or 96K Byte SRAM Byte SRAM

256K or 512K 256K or 512K Byte Burst Byte Burst

FlashFlash

OTP OTP MemMem

UARTUARTI2CI2CSPISPITIMTIMRTCRTC

EXT. EXT. Bus Bus

GPIOGPIO

USB USB 2.0FS 2.0FS

CAN CAN 2.0B 2.0B

Enet Enet MAC MAC

PFPFQ Q

BC BC

DMADMA

INTINTR R

CntlCntl

ARM96ARM966E 6E CORE CORE

w/DSPw/DSP96 MHz 96 MHz

CLK CLK CntlCntl

ADCADC

LVD LVD BODBOD

PLLPLL JTAJTAGG

ETMETM99

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Synchronous Serial Peripheral (SSP)

SSP is serial high-speed bus system Display, AD- & DA converters

SSP is always used in a master-slave mode Master is responsible for the clock generation

SSP works in a duplex mode MOSI & MISO

EIA: Electronic Industry Alliance

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SSP Hardware flow control

Participant 1

7 0

Clock generator Data input parallel

Data output parallel

Participant n

7 0

Data input parallel

Date output parallel

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SSP features

Master & Slave modes Programmable choice of interface operation

Motorola SPI National Microwire TI synchronous serial

Programmable data frame size from 4 to 16 bits Programmable bit rate and Internal clock prescaler Separate transmit and receive FIFO buffers

16 bits wide and 8 locations deep Support for DMA Independent masking of transmit & receive FIFO

interrupts Internal loopback test mode Dynamic change from “Master Slave” or “Slave

Master”

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SSP Block diagram

Ref manual figure 74

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SSP Pin description

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SSP register map

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SSP Configuration (1/3)

SSP Control Register 0 (SSP_CR0) Frame Format bits (FRF)

Select one of the three protocols• Motorola SPI• Texas Instruments SSI• National Semiconductor Microwire

Data Size Select bits (DSS) Select the data word size

Serial Clock Rate bits (SCR) Fix the transmit and receive bit rates from the SPI Master

Clock

CPHA & CPOL bits Clock Phase and Polarity, applicable to Motorola SPI format

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SSP Configuration (2/3)

SSP Control Register 1 (SSP_CR1) Master or Slave (MS) selection bit

To configure the SSP as a master (MS = 0) or slave (MS = 1)

SSP Enable (SSE) To enable the SSP (SSE = 1)

SSP Presale Register (SSP_PR) Clock Presale Register bits

Fix the SPI Master Clock

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SSP Configuration (3/3)

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Pin connections of SSP

STR91x ARM966 manual 12274.pdf, 4.1 pin functions page 36

P5.4 UART0_SCLK Alternate Output 2P5.5 UART0_MOSI Alternate Output 2P5.6 UART0_MISO Alternate Input 1P5.7 GPIO_5.7 Alternate Output 1

Use the SD Card adapter of MCBSTR9. Which port?

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File system (FS)

FS is a method for storing & organizing computer files

FS use data storage devices Hard disk, CD-ROM, SD cards …

Array of fixed size blocks, called sectors (512, 1k, 2k or 4k bytes)

File system organize these sectors into files and directories

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Type of FS

Disk file system Storage of the files on disk drive

FAT, NTFS and HFS

Flash file system Storage of the files on flash memory devices

MMC or SD cards

Network file system Acts as a client for remote file access

NFS (Network File System) AFS (Andrew File System) SMB (Server Message Block)

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Secure Digital (SD) Memory Card

SD is a non volatile memory card Developed by Matsushita, ScanDisk and Toshiba

Use range of SD Cards Digital cameras Handheld computers PDAs mobile phones GPS receivers video game consoles

Capacities range from 4 MB to 2 GB

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Pin assignments

Pin no. Symbol Direction

Description

In Out

1 CS Chip select

2 DI Data in

3 VSS GND

4 VDD VCC

5 SCLK Clock

6 VSS2 GND

7 DO Data out

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Structure of FAT partition disc

Boot sector, BIOS Parameter Block with some basic information about the file

system Boot loader of the operating system

FAT Region This region contains two copies of the File Allocation Table

Root Directory Region. Information about the files and directories located in the root

directory

Data Region. This region contains the files and directories

Files are allocated entirely in a cluster If a 1 KB file resides in a 32 KB cluster, 31 KB are wasted

Bootsector

File Allocation Table 2

File Allocation Table 2

RootDirectory(FAT12/16 only)

Data Region (for files and directories)

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File Allocation Table (FAT)

A partition is divided up into identically sized clusters Cluster sizes vary between 2 KB and 32 KB.

Each file may occupy one or more of these clusters A File is represented by a chain of these clusters (singly

linked list)

FAT contains information about the clusters Each entry records one of five things

The cluster number of the next cluster in a chain A special end of cluster chain (EOC) A special entry to mark a bad cluster A special entry to mark a reserved cluster A zero to note that the cluster is unused

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File Allocation Table (example)

Number Value Meaning

Cluster 1 0000 Empty

Cluster 2 0003 Used

Cluster 3 0004 Used

Cluster 4 0006 Used

Cluster 5 0001 Reserved

Cluster 6 0007 Used

Cluster 7 FFFF EOF

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Directory table

A directory table is a special type of file that represents a directory Its files or directories are represented by a 32-byte entries

Name Extension Attributes (archive, hidden, read-only) Date & time of creation Address of the first cluster Size of the file/directory

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Application Interface (API) of a FS

The file are represented with FILE objects

The read & write functions need a pointer to the FILE objects fopen()

Furnishes a pointer to the given FILE object

Example #include <stdio.h>

FILE *FilePointer;

FilePointer = fopen ("c:\\Text.txt", "w");

if (FilePointer == NULL) {

printf ("Error, the file could not be opened !\n");

}

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FILE *fopen (char filename[], char mode[])

First argument of the fopen function File name

Second argument of the fopen function Access type

"r" Open the file for read"w" Create the file for write"a" Create or open the file for write at the end

of it"r+" Open the file for update (read and write)"w+" Create the file for update "a+" Create or open the file for update at the

end of it

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int fclose (FILE *stream)

When the file will not be used The link to the file must be close with fclose()

Example fclose (FilePointer);

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Function to read from or print into files

Key board/screen Function

File

printf("v = %d", i) Formatted output

fprintf(FilePointer, "v = %d", i)

scanf("%f", f) Formatted input

fscanf(FilePointer, "%f", f)

c = getchar() Read a character

c = fgetc(FilePointer)

putchar(c) Write a character

fputc(c, FilePointer)

gets(Buffer) Read a sentence

fgets(Buffer,Maxlength,FilePointer)

puts(Text) Write a sentence

fputs(Text, FilePointer)