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ZTEX EZ-USB FX2 SDK - Beispiel
Das SDK-Paket enthält viele nützliche Beispiele, z.B. zum Ansteuern des Speichers,
für schnelle USB-Übertragungen via EZ-USB FX2 und für den Zugriff auf Flash-Speicher.
Das folgende Beispiel für ZTEX USB-FPGA Boards
gibt einen Eindruck über die Vorteile des Makro-Ansatzes des Firmware-Entwicklungskits und des Java-API's.
Die Firmware (definiert in ucecho.c) legt die Endpoints 2 und 4 fest
(beide 512 Bytes, doppel-gepuffert, Bulk-Transfer, zu Interface 0 gehörig).
Alle zum Endpoint 4 geschriebenen Daten werden vom FPGA in Großbuchstaben konvertiert
und können von Endpoint 2 zurückgelesen werden.
Der Bitstream für die FPGA-Konfiguration / -Programmierung wird in fpga/ucecho.vhd definiert.
Das FPGA liest pro Taktzyklus ein Byte von Port PC, konvertiert es in Großbuchstaben und schreibt es nach Port PB zurück.
Sie Hostsoftware (definiert in UCEcho.java) sendet Benutzer-Strings zum Gerät und liest diese zurück.
Das Hochladen der Firmware (ucecho.ihx) in dem EZ-USB FX2-Mikrocontroller und
das Hochladen des Bitstreams (fpga/ucecho.bin) in das FPGA erfolgt mit Hilfe der Java API.
Das Beispiel ist ein Teil des Pakets und kann als guter Startpunkt für eigene Projekte dienen.
Firmware: ucecho.c
Dies ist der C-Quellcode für die Firmware:
#include[ztex-conf.h] // Loads the configuration macros, see ztex-conf.h for the available macros
#include[ztex-utils.h] // include basic functions
// Cypress vendor ID and product ID may only (!) be used for experimental purposes
SET_VPID(0x4b4,0x8613);
// define endpoints 2 and 4, both belong to interface 0 (in/out are from the point of view of the host)
EP_CONFIG(2,0,BULK,IN,512,2);
EP_CONFIG(4,0,BULK,OUT,512,2);
// identify as ZTEX USB FPGA Module 1.2 (Important for FPGA configuration)
IDENTITY_UFM_1_2(1.0.0.0,0);
// give them a nice name
#define[PRODUCT_STRING]["ucecho for USB FPGA MODULE 1.2"]
// this is called automatically after FPGA configuration
#define[POST_FPGA_CONFIG][POST_FPGA_CONFIG
OEC = 255;
]
// include the main part of the firmware kit, define the descriptors, ...
#include[ztex.h]
void main(void)
{
WORD i,size;
// init everything
init_USB();
EP2CS &= ~bmBIT0; // stall = 0
SYNCDELAY;
EP4CS &= ~bmBIT0; // stall = 0
SYNCDELAY; // first two packages are waste
EP4BCL = 0x80; // skip package, (re)arm EP4
SYNCDELAY;
EP4BCL = 0x80; // skip package, (re)arm EP4
while (1) {
if ( !(EP4CS & bmBIT2) ) { // EP4 is not empty
size = (EP4BCH << 8) | EP4BCL;
if ( size>0 && size<=512 && !(EP2CS & bmBIT3)) { // EP2 is not full
for ( i=0; i<size; i++ ) {
IOC = EP4FIFOBUF[i]; // data from EP4 is converted to uppercase by the FPGA ...
EP2FIFOBUF[i] = IOB; // ... and written back to EP2 buffer
}
EP2BCH = size >> 8;
SYNCDELAY;
EP2BCL = size & 255; // arm EP2
}
SYNCDELAY;
EP4BCL = 0x80; // skip package, (re)arm EP4
}
}
}
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Bitstream: fpga/ucecho.vhd
Dies ist der VHDL-Quellcode für den FPGA-Bitstream:
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
--
entity ucecho is
port(
pc : in unsigned(7 downto 0);
pb : out unsigned(7 downto 0);
CLK : in std_logic
);
end ucecho;
--
--
--signal declaration
architecture RTL of ucecho is
--
begin
dpUCECHO: process(CLK)
begin
if CLK' event and CLK = '1' then
if ( pc >= 97 ) and ( pc <= 122)
then
pb <= pc - 32;
else
pb <= pc;
end if;
end if;
end process dpUCECHO;
--
end RTL;
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Java-Hostsoftware: UCEcho.java
Dies ist der Java-Quellcode für die Hostsoftware:
import java.io.*;
import java.util.*;
import ch.ntb.usb.*;
import ztex.*;
// *****************************************************************************
// ******* ParameterException **************************************************
// *****************************************************************************
// Exception the prints a help message
class ParameterException extends Exception {
public final static String helpMsg = new String (
"Parameters:\n"+
" -d <number> Device Number (default: 0)\n" +
" -f Force uploads\n" +
" -p Print bus info\n" +
" -h This help" );
public ParameterException (String msg) {
super( msg + "\n" + helpMsg );
}
}
// *****************************************************************************
// ******* Test0 ***************************************************************
// *****************************************************************************
class UCEcho extends Ztex1v1 {
// ******* UCEcho **************************************************************
// constructor
public UCEcho ( ZtexDevice1 pDev ) throws UsbException {
super ( pDev );
}
// ******* claimInterface ******************************************************
// claims interface 0
public void claimInterface ( ) throws UsbException{
if ( LibusbJava.usb_claim_interface(handle(), 0) < 0 )
throw new UsbException("Claiming interface 0 failed: " + LibusbJava.usb_strerror());
}
// ******* releaseInterface ****************************************************
// releases interface 0
public void releaseInterface ( ) {
LibusbJava.usb_release_interface(handle(), 0);
}
// ******* echo ****************************************************************
// writes a string to Endpoint 4, reads it back from Endpoint 2 and writes the output to System.out
public void echo ( String input ) throws UsbException {
byte buf[] = input.getBytes();
int i = LibusbJava.usb_bulk_write(handle, 4, buf, buf.length, 1000);
if ( i<0 )
throw new UsbException("Error sending data: " + LibusbJava.usb_strerror());
System.out.println("Send "+i+" bytes: `"+input+"'" );
try {
Thread.sleep( 10 );
}
catch ( InterruptedException e ) {
}
buf = new byte[1024];
i = LibusbJava.usb_bulk_read(handle, 2, buf, 1024, 1000);
if ( i<0 )
throw new UsbException("Error receiving data: " + LibusbJava.usb_strerror());
System.out.println("Read "+i+" bytes: `"+new String(buf,0,i)+"'" );
}
// ******* main ****************************************************************
public static void main (String args[]) {
int devNum = 0;
boolean force = false;
try {
// init USB stuff
LibusbJava.usb_init();
// scan the USB bus
ZtexScanBus1 bus = new ZtexScanBus1( ZtexDevice1.cypressVendorId, ZtexDevice1.cypressProductId, true, false, 1);
if ( bus.numberOfDevices() <= 0) {
System.err.println("No devices found");
System.exit(0);
}
// scan the command line arguments
for (int i=0; i<args.length; i++ ) {
if ( args[i].equals("-d") ) {
i++;
try {
if (i>=args.length) throw new Exception();
devNum = Integer.parseInt( args[i] );
}
catch (Exception e) {
throw new ParameterException("Device number expected after -d");
}
}
else if ( args[i].equals("-f") ) {
force = true;
}
else if ( args[i].equals("-p") ) {
bus.printBus(System.out);
System.exit(0);
}
else if ( args[i].equals("-h") ) {
System.err.println(ParameterException.helpMsg);
System.exit(0);
}
else throw new ParameterException("Invalid Parameter: "+args[i]);
}
// create the main class
UCEcho ztex = new UCEcho ( bus.device(devNum) );
// upload the firmware if necessary
if ( force || ! ztex.valid() || ! ztex.dev().productString().equals("ucecho for USB FPGA MODULE 1.2") ) {
ztex.uploadFirmware( "ucecho.ihx", force );
}
// upload the bitstream if necessary
if ( force || ! ztex.getFpgaConfiguration() ) {
System.out.println("FPGA configuration time: " + ztex.configureFpga( "fpga/ucecho.bin" , force ) + " ms");
}
// claim interface 0
ztex.claimInterface();
// read string from stdin and write it to USB device
String str = "";
BufferedReader reader = new BufferedReader( new InputStreamReader( System.in ) );
while ( ! str.equals("quit") ) {
System.out.print("Enter a string or `quit' to exit the program: ");
str = reader.readLine();
ztex.echo(str);
System.out.println("");
}
// release interface 0
ztex.releaseInterface();
}
catch (Exception e) {
System.out.println("Error: "+e.getLocalizedMessage() );
}
}
}
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C-Hostsoftware: UCEcho.c
Es ist ebenfalls möglich mittels anderer Programmiersprachen und libusb auf das Gerät zuzugreifen. In diesem Fall muss die Firmware aber mittels des im
SDK enthaltenen FWLoader Werkzeugs hochgeladen werden.
Der C-Quellcode für die Hostsoftware lautet:
/*!
UCEcho -- C host software for ucecho examples
Copyright (C) 2009-2010 ZTEX GmbH
http://www.ztex.de
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 3 as
published by the Free Software Foundation.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see http://www.gnu.org/licenses/.
!*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <usb.h>
#define BUFSIZE 256
struct usb_device *device;
usb_dev_handle *handle;
char buf[BUFSIZE];
// find the first ucecho device
struct usb_device *find_device ()
{
struct usb_bus *bus_search;
struct usb_device *device_search;
bus_search = usb_busses;
while (bus_search != NULL)
{
device_search = bus_search->devices;
while (device_search != NULL)
{
if ( (device_search->descriptor.idVendor == 0x221a) && (device_search->descriptor.idProduct == 0x100) )
{
handle = usb_open(device_search);
usb_get_string_simple(handle, device_search->descriptor.iProduct, buf, BUFSIZE);
if ( ! strncmp("ucecho", buf , 6 ) )
return device_search;
usb_close(handle);
}
device_search = device_search->next;
}
bus_search = bus_search->next;
}
return NULL;
}
// main
int main(int argc, char *argv[])
{
usb_init(); // initializing libusb
usb_find_busses(); // ... finding busses
usb_find_devices(); // ... and devices
device = find_device(); // find the device (hopefully the correct one)
if ( device == NULL ) { // nothing found
fprintf(stderr, "Cannot find ucecho device\n");
return 1;
}
if (usb_claim_interface(handle, 0) < 0) {
fprintf(stderr, "Error claiming interface 0: %s\n", usb_strerror());
return 1;
}
while ( strcmp("QUIT", buf) ) {
// read string from stdin
printf("Enter a string or `quit' to exit the program: ");
scanf("%s", buf);
// write string to ucecho device
int i = usb_bulk_write(handle, 0x04, buf, strlen(buf)+1, 1000);
if ( i < 0 ) {
fprintf(stderr, "Error sending data: %s\n", usb_strerror());
return 1;
}
printf("Send %d bytes: `%s'\n", i , buf);
// read string back from ucecho device
i = usb_bulk_read(handle, 0x82, buf, BUFSIZE, 1000);
if ( i < 0 ) {
fprintf(stderr, "Error readin data: %s\n", usb_strerror());
return 1;
}
printf("Read %d bytes: `%s'\n", i , buf);
}
usb_release_interface(handle, 0);
usb_close(handle);
return 0;
}
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Beispielaufruf
Es folgt ein Beispielaufruf mit Ausgabe:
stefan@ws2:/drv_a2/usb-fpga/ztex-1.1/examples/usb-fpga-1.2/ucecho$ java -cp UCEcho.jar UCEcho
FPGA configuration time: 1353 ms
Enter a string or `quit' to exit the program: Hello world!
Send 12 bytes: `Hello world!'
Read 12 bytes: `HELLO WORLD!'
Enter a string or `quit' to exit the program: quit
Send 4 bytes: `quit'
Read 4 bytes: `QUIT'
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