seminar code
05-08-2014, 01:07 PM
Implementation of a USB Slave to Slave File Transfer Device Using Microcontrollers
[attachment=66602]
NTRODUCTION
As the development of USB enabled peripherals increases, the
Universal Serial Bus (USB) has rapidly become a de facto standard
in communication with the Personal Computer (PC) and has lead to
new technologies for interfacing memory devices. These
memory/storage devices connect to the USB ports and appear as
removable storage device in personal computers, the most popular
of which is the USB Flash Drive. The disadvantage of using USB
Flash Drives is that it requires a PC to initiate file transfers
between one another. [10]
As a solution to the USB Flash Drive disadvantage, the
research project aims to develop a device that allows file transfers
between two USB memory devices without the need for a Personal
USB SLAVE TO SLAVE FILE TRANSFER DEVICE
The USB Slave to Slave File Transfer Device is a device that
facilitates file and folder/directory transfers from one flash drive to
another flash drive using the USB 1.1 interface without the need for
a Personal Computer (PC) to act as mediator. Figure 1 shows the
system setup while figure 2 shows the general block diagram of the
system.
The system allows the user to select files or folders/directories
for copying from a source flash drive to a user selectable directory
in the destination flash drive. The device also supports a copy all
function, which works the same way. Contents of the flash drives
are displayed in their 8.3 filename format thru a twenty character
by four lines - sized dot-matrix character liquid crystal display
ser Interface Controller Module
This module is responsible for obtaining user input and
displaying user requested information thru an LCD. It consists of
three submodules namely the LCD Controller, Navigation and
Screen Display Formatter (as shown in figure 3).
Navigation
The Navigation submodule is the input handling hardware of
the system. This submodule includes six input buttons and
circuitry for filtering the input signals. The Navigation submodule
sends a corresponding signal for each button press to the
microcontroller that controls the LCD so that it could update the
screen and/or send commands to the File System Controller module
for processing (i.e. opening a folder and initiate a copy command).
Figure 5 shows the button layout of the Navigation submodule
Screen Display Formatter
The Screen Display Formatter submodule is responsible for
arranging and ordering the contents of the LCD screen. It formats
the screen to display the appropriate option menus, folder
contents, path names, content type (folder or file).
The Screen Display Formatter submodule is the software part
of the User Interface module. It receives the names of the files and
folders to be displayed from the File System Controller module.
Figure 6 shows how the screen is formatted.
USB Controller Module
The USB Controller module is responsible for starting-up the
system, handling the packets, computation and checking of error
checking bits, packet encoding, conversion of packets from parallel
to serial and vice versa and NRZI decoding and encoding. This
module accepts the commands to either read or write onto a USB
flash drive as requested by the File System Controller Module.
Input from the USB flash drives is the result of an earlier request
for data. These requests include content information (i.e. file
names), actual content (i.e. files) or identification signals (i.e. the
connected USB device is checked if it falls under the Mass Storage
Class (MSC) or Human Interface Device (HID)). Block diagram is
shown in figure 8. [1] [2]
The module also governs the data that needs to be transmitted
to the USB Flash Drives, as well as process and send the results of
the transaction to the File System Controller Module. In addition,
the module also sends notifications to alert the user of the status of
the system or
ONCLUSION
The design of the microcontroller system is based on the
simplified schematic of the CY4640 Mass Storage Reference
Design Kit (RDK), which uses the Cypress CY7C67300 USB
Host/Peripheral Controller. The external Serial EEPROM initially
holds the user’s program before it is loaded to the USB
Host/Peripheral chip. Since only 15K bytes of the USB
Host/Peripheral Controller’s internal memory is allocated for the
user’s program and data, it is not sufficient to hold the working
program of the prototype. An external SRAM was included in the
design to compensate for the lack of internal memory. The RS232
Transceiver is required by the LCD Module as well as for
debugging with the PC’s HyperTerminal. The USB
Host/Peripheral Controller requires a 12MHz clock source from
which an internal Phase Lock Loop (PLL) produces a 48MHz
internal clock. The same software used with the Cypress RDK is
[attachment=66602]
NTRODUCTION
As the development of USB enabled peripherals increases, the
Universal Serial Bus (USB) has rapidly become a de facto standard
in communication with the Personal Computer (PC) and has lead to
new technologies for interfacing memory devices. These
memory/storage devices connect to the USB ports and appear as
removable storage device in personal computers, the most popular
of which is the USB Flash Drive. The disadvantage of using USB
Flash Drives is that it requires a PC to initiate file transfers
between one another. [10]
As a solution to the USB Flash Drive disadvantage, the
research project aims to develop a device that allows file transfers
between two USB memory devices without the need for a Personal
USB SLAVE TO SLAVE FILE TRANSFER DEVICE
The USB Slave to Slave File Transfer Device is a device that
facilitates file and folder/directory transfers from one flash drive to
another flash drive using the USB 1.1 interface without the need for
a Personal Computer (PC) to act as mediator. Figure 1 shows the
system setup while figure 2 shows the general block diagram of the
system.
The system allows the user to select files or folders/directories
for copying from a source flash drive to a user selectable directory
in the destination flash drive. The device also supports a copy all
function, which works the same way. Contents of the flash drives
are displayed in their 8.3 filename format thru a twenty character
by four lines - sized dot-matrix character liquid crystal display
ser Interface Controller Module
This module is responsible for obtaining user input and
displaying user requested information thru an LCD. It consists of
three submodules namely the LCD Controller, Navigation and
Screen Display Formatter (as shown in figure 3).
Navigation
The Navigation submodule is the input handling hardware of
the system. This submodule includes six input buttons and
circuitry for filtering the input signals. The Navigation submodule
sends a corresponding signal for each button press to the
microcontroller that controls the LCD so that it could update the
screen and/or send commands to the File System Controller module
for processing (i.e. opening a folder and initiate a copy command).
Figure 5 shows the button layout of the Navigation submodule
Screen Display Formatter
The Screen Display Formatter submodule is responsible for
arranging and ordering the contents of the LCD screen. It formats
the screen to display the appropriate option menus, folder
contents, path names, content type (folder or file).
The Screen Display Formatter submodule is the software part
of the User Interface module. It receives the names of the files and
folders to be displayed from the File System Controller module.
Figure 6 shows how the screen is formatted.
USB Controller Module
The USB Controller module is responsible for starting-up the
system, handling the packets, computation and checking of error
checking bits, packet encoding, conversion of packets from parallel
to serial and vice versa and NRZI decoding and encoding. This
module accepts the commands to either read or write onto a USB
flash drive as requested by the File System Controller Module.
Input from the USB flash drives is the result of an earlier request
for data. These requests include content information (i.e. file
names), actual content (i.e. files) or identification signals (i.e. the
connected USB device is checked if it falls under the Mass Storage
Class (MSC) or Human Interface Device (HID)). Block diagram is
shown in figure 8. [1] [2]
The module also governs the data that needs to be transmitted
to the USB Flash Drives, as well as process and send the results of
the transaction to the File System Controller Module. In addition,
the module also sends notifications to alert the user of the status of
the system or
ONCLUSION
The design of the microcontroller system is based on the
simplified schematic of the CY4640 Mass Storage Reference
Design Kit (RDK), which uses the Cypress CY7C67300 USB
Host/Peripheral Controller. The external Serial EEPROM initially
holds the user’s program before it is loaded to the USB
Host/Peripheral chip. Since only 15K bytes of the USB
Host/Peripheral Controller’s internal memory is allocated for the
user’s program and data, it is not sufficient to hold the working
program of the prototype. An external SRAM was included in the
design to compensate for the lack of internal memory. The RS232
Transceiver is required by the LCD Module as well as for
debugging with the PC’s HyperTerminal. The USB
Host/Peripheral Controller requires a 12MHz clock source from
which an internal Phase Lock Loop (PLL) produces a 48MHz
internal clock. The same software used with the Cypress RDK is