AN84868
Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
Author: Rama Sai Krishna. V
Associated Project: Yes
Associated Part Family: CYUSB3014
For latest FX3 SDK: click here
Related Application Notes: AN75705, AN65974
®
®
AN84868 shows you how to configure a Xilinx FPGA over a slave serial interface using EZ-USB FX3™, which is the
next-generation USB 3.0 peripheral controller. This interface lets you download configuration files into a Xilinx FPGA over
USB 2.0 or 3.0. The firmware files with this application note are designed and tested for Xilinx FPGAs, but you can
customize them for other FGPAs with a similar interface. For complete list of USB SuperSpeed Code Examples, visit
http://www.cypress.com/documentation/code-examples/usb-superspeed-code-examples.
Contents
1
2
3
1
Introduction ...............................................................1
Xilinx Slave Serial Configuration Interface ................2
Implementation .........................................................3
3.1
Hardware Details .............................................3
3.2
FX3 Firmware ..................................................4
3.3
I/O Matrix Configuration ...................................6
3.4
Slave Serial Interface Implementation .............9
3.5
Reconfiguring the I/O Matrix .......................... 10
3.6
Integrating the Configuration
Firmware into Your Design ............................ 11
3.7
Software Details ............................................ 11
4
Operating Instructions ............................................ 12
5
Summary ................................................................ 18
6
Associated Project Files ......................................... 18
7
References ............................................................. 19
About the Author ............................................................. 19
Document History............................................................ 20
Worldwide Sales and Design Support ............................. 21
Introduction
FX3 has a configurable, parallel General Programmable Interface (GPIF II) that can connect to external devices like
image sensors, external processors, ASICs, or FPGAs. As a result, users can integrate USB 3.0 capability into
almost any system.
2
2
In addition, FX3 provides interfaces to connect to serial peripherals such as UART, SPI, I C, and I S.
FX3 allows you to add SuperSpeed capability to any FPGA-based design. In most applications, FPGA acts as a
master and the GPIF II operates in a synchronous Slave FIFO interface. For more details on the Slave FIFO
interface, see AN65974 – Designing with the EZ-USB® FX3™ Slave FIFO Interface.
You can configure the FPGA using the controller (in this case, FX3) connected to it. Using FX3 eliminates the need
for a dedicated configuration chip (for example, a PROM or a processor) for the FPGA. In addition, this method can
act as a replacement for the popular JTAG configuration interface that requires JTAG connectors on the board. This
method reduces the cost and board space.
Acting as a master, FX3 can configure the Xilinx FPGA in two modes: Slave Parallel (SelectMAP) and Slave Serial.
See the Xilinx Spartan-6 FPGA Configuration User Guide to get information on the various options to configure an
FPGA. This application note describes only the Slave Serial mode. It also describes how FX3 firmware switches to
the Slave FIFO interface after the FPGA configuration is complete. Figure 1 shows a block diagram in which FX3
configures the FPGA at the start and then switches to the Slave FIFO interface after the configuration is successful.
The following sections examine the details of the Xilinx Slave Serial configuration interface and its design
implementation using FX3.
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Document No. 001-84868 Rev. *C
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
Figure 1. System-Level Application Block Diagram
After FPGA Configuration
is Done Successfully
PC
GPIF II
Configured as
Slave FIFO
Interface
FPGA
Configuration
Utility
USB
Cyusb
3.sys
USB
Interface
Block
Bank
I/O
FX3
Bank
I/O
Rest of the User’s
System
FPGA
Configuration
I/Os (SPI Lines
and Few
GPIOs)
Config
I/O
During
Configuration
2
Xilinx Slave Serial Configuration Interface
This section describes the details of Xilinx Slave Serial interface. Figure 2 shows the interface pins associated with
the Xilinx Slave Serial interface and Table 2 contains the description of Slave Serial interface pins.
Figure 2. Hardware Connections Between FX3 and Xilinx Spartan-6 FPGA
VDD
4.7 KΩ
FX3
4.7 KΩ
330 Ω
SPI_SSN
PROGRAM_B
GPIO[52]
INIT_B
SPI_CLOCK
CCLK
SPI_MOSI
DIN
GPIO[50]
Xilinx
FPGA
DONE
PROGRAM_B, INIT_B, and DONE are open-drain signals. Connect pull-up resistors of suitable value on these lines.
The resistor values mentioned in Figure 2 are taken from the Xilinx Spartan-6 FPGA Configuration User Guide. Note
that there is no need to connect these pull-up resistors if the FX3 DVK is used, but pull-up resistors should be placed
in the final design.
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
Table 1 shows the interface signals in the Slave Serial interface.
Table 1. Xilinx Slave Serial Configuration Pin Description
Pin Name
PROGRAM_B
Pin Direction (to FPGA)
Pin Description
Program FPGA. Active LOW.
Input
When asserted LOW for 500 ns or longer (300 ns in the Spartan-3 FPGAs), it
forces the FPGA to restart its configuration process by clearing configuration
memory.
INIT_B
Open drain bidirectional I/O
FPGA Initialization Indicator. Drives LOW after power-on reset (POR) or when
PROGRAM_B pulses LOW while the FPGA is clearing its configuration memory. If
a CRC error is detected during configuration, FPGA again drives INIT_B LOW.
CCLK
Input
Configuration Clock.
DIN
Input
Data Input. Serial data. FPGA captures data on rising CCLK edge.
DONE
Open drain bidirectional I/O
FPGA Configuration Done. LOW during configuration. Goes HIGH when FPGA
successfully completes configuration.
Figure 3 shows the clocking sequence diagram of the Xilinx Slave Serial configuration.
Figure 3. Xilinx Slave Serial Configuration Clocking Sequence
3
Implementation
FX3 starts the configuration by pulsing PROGRAM_B and monitoring the INIT_B pin. When the INIT_B pin goes
HIGH, the FPGA is ready to receive data. The FX3 then starts supplying data and clock signals until either the DONE
pin goes HIGH, indicating a successful configuration, or until the INIT_B pin goes LOW, indicating a configuration
error. The configuration process requires more clock cycles than indicated from the configuration file size. These
additional clocks are required during the FPGA’s startup (see Figure 3).
3.1
Hardware Details
3.1.1
Hardware Boards
Xilinx SP601 Evaluation Kit
Wires to interconnect configuration signals
SuperSpeed Explorer Kit (CYUSB3KIT-003) or EZ-USB FX3 DVK
Samtec-to-FMC interconnection board (for FX3 DVK) or CYUSB3ACC005 Interconnection board (for
CYUSB3KIT-003).
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
The SPI hardware block in FX3 serializes the configuration data from the PC. The SPI_SSN (slave select),
SPI_CLOCK, and SPI_MOSI of FX3 are connected to the PROGRAM_B, CCLK, and DIN of the Xilinx FPGA,
respectively. The INIT_B and DONE pins of the FPGA are connected to GPIOs 52 and 50, respectively. Figure 2
shows the connections between FX3 and the Xilinx FPGA.
3.2
FX3 Firmware
The attached firmware has the following parts:
Configuration of the Xilinx FPGA connected to FX3 over the Slave Serial interface.
The Slave FIFO interface configuration works exactly the same as described in AN65974 if the Xilinx FPGA
configuration is successful.
The SPI hardware block in FX3 serializes the data that FX3 receives from the PC application “FPGA Configuration
Utility,” as Figure 1 shows. The FPGA Configuration Utility is designed to identify the USB devices with Cypress VID
(0x04B4) and PID (0x00F1).
Review the FX3 application structure chapter of the FX3 Programmer’s Manual to learn the structure of application
firmware. Use the FX3 Firmware API Guide as a reference for more details on the FX3 SDK APIs.
Table 2 describes the files present in the firmware source code, which is attached to this application note.
Table 2. Description of FX3 Firmware Source Files
File Name
Description
cyfx_gcc_startup.S
Cypress FX3 firmware startup code
cyfxconfigfpga.c
This file illustrates the configuration of FPGA in a Slave Serial mode example. It contains the following
functions:
Main: Initializes the FX3 device, sets up caches, configures the FX3 I/Os, and starts the RTOS kernel.
CyFxConfigFpgaApplnInit: Initializes the FX3 GPIO and SPI modules. Configure GPIO[50] and
GPIO[52] as input signals. Initializes the FX3 USB block for enumeration.
CyFxConfigFpgaApplnStart: Endpoint configuration for USB transfers and DMA channel
configuration for data transfers from USB block to SPI block of FX3.
CyFxConfigFpgaApplnStop: Deinitializes the FX3 GPIO and SPI modules to allow reconfiguration
of the I/O matrix.
CyFxConfigFpga: Writes configuration data to the Xilinx FPGA over the Slave Serial interface.
cyfxconfigfpga.h
This file contains the constants and definitions used by the Configure FPGA application example.
cyfxslfifosync.c
This file illustrates the Slave FIFO Synchronous mode example. It contains the following functions:
www.cypress.com
CyFxApplicationDefine: Creates an application thread to perform data transfers over the Slave
FIFO interface.
SlFifoAppThread_Entry: Application thread function that calls initialization functions for internal
blocks of FX3. Waits for the events to configure FPGA and switches to the Slave FIFO interface once
the FPGA configuration is successful.
CyFxSwitchtoslFifo: Reconfigures the FX3 I/O matrix per the Slave FIFO interface requirement.
CyFxSlFifoApplnInit: Initializes the processor interface block, loads the GPIF configuration for
the Slave FIFO interface, and starts the GPIF state machine.
CyFxSlFifoApplnStart: Endpoint configuration for USB transfers and DMA channel configuration
for data transfers between the USB block and the GPIF II block of FX3.
CyFxSlFifoApplnStop: This function stops the Slave FIFO application. This is called whenever a
RESET or DISCONNECT event is received from the USB host. The endpoints are disabled, and the
DMA channel is destroyed by this function.
CyFxSlFifoApplnUSBEventCB: Handles USB events such as suspend, cable disconnect, reset,
and resume.
CyFxSlFifoApplnUSBSetupCB: Callback to handle the USB setup requests.
CyFxSlFifoApplnDebugInit: Initializes the FX3 UART block for printing debug messages. The
debug prints are routed to the UART and can be seen using a UART console running at 115200 baud.
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
File Name
Description
cyfxslfifosync.h
This file contains the constants and definitions used by the Slave FIFO application.
cyfxslfifousbdscr.c
This file contains the USB descriptors needed for the Slave FIFO example.
cyfxtx.c
This file defines the porting required for the ThreadX RTOS. It is provided in source form and must be
compiled with the application source code.
cyfxgpif2config.h
This file contains the GPIF II descriptors for the 16-bit and 32-bit Slave FIFO interface.
Note See the “FX3 Terminology” section in the Getting Started with EZ-USB FX3 application note to learn the terms
specific to FX3.
The flow chart in Figure 4 describes the FX3 firmware.
Figure 4. FX3 Firmware Flow Chart
Start Main Function
IO Matrix
matrixConfiguration
configurationtotoEnable
enableSPI
SPI and
and GPIOs
GPIOs
IO
SPImodule
Module initialization
Initialization
SPI
GPIOs
Configuration
GPIOs configuration
Load USB
USB descriptors
Load
Descriptors of
of final
Finalapplication
Application and
and
Enumerate
enumerate
StartManual
main function
Create aa DMA
DMA
manual
channel between
USB
Create
Channel
Between USB
Producer
Consumer socket
Socketto
to
producerSocket
socket and
and CPU
CPU consumer
Transfer
SPI
transfer Configuration
configuration Data
data Through
through SPI
Wait for
Wait
for aa Vendor
vendor Command
command
Send Status of FPGA
Send status of FPGA configuration
Configuration to FPGA
to FPGA
configuration
utility
Configuration
Utility
Vendor
Command
command
Start
Start Configuring
configuring FPGA
FPGA
Is configuration
Configuration
Successful
Successful
De-initialize SPI module
De-initialize
SPI Module
Switch to final
application,
in this case Slave
Switch to Final Application, in this case Slave
FIFO interface.
FIFO interface.
Reconfigure
the
IO
matrix
if theApplication
final
Reconfigure the IO Matrix if the final
application
requires Set
a different
set of IO
Requires
a Different
of IO Resources
resources
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
3.3
I/O Matrix Configuration
In the main() function, configure the I/O matrix (shown in the following code) according to the application
requirement. The GPIF II interface is configured to 16-bit to enable the SPI interface. GPIOs 50 and 52 are enabled
to connect with the DONE and INIT_B pins of the Xilinx FPGA (see Figure 2 for the hardware interface diagram). You
can find this piece of code in the function main()present in file cyfxconfigfpga.c.
io_cfg.useUart
io_cfg.useI2C
io_cfg.useI2S
io_cfg.useSpi
io_cfg.isDQ32Bit
io_cfg.lppMode
=
=
=
=
=
=
CyTrue;
CyFalse;
CyFalse;
CyTrue;
CyFalse;
CY_U3P_IO_MATRIX_LPP_DEFAULT;
/* GPIOs 50 and 52 are enabled. */
io_cfg.gpioSimpleEn[0] = 0x00000000;
io_cfg.gpioSimpleEn[1] = 0x00140000;
io_cfg.gpioComplexEn[0] = 0;
io_cfg.gpioComplexEn[1] = 0;
status = CyU3PDeviceConfigureIOMatrix (&io_cfg);
3.3.1
SPI Module Initialization
The SPI module is initialized and configured by the following code. It is configured to run at a 25-MHz clock
frequency. The FX3 SPI hardware block can support up to a 33-MHz clock frequency. You can find this piece of code
in the function CyFxConfigFpgaApplnInit()present in the file cyfxconfigfpga.c
/* Start the SPI module and configure the master. */
apiRetStatus = CyU3PSpiInit();
/* Start the SPI master block. Run the SPI clock at 25MHz and configure
the word length to 8 bits. Also configure the slave select using FW. */
CyU3PMemSet ((uint8_t *)&spiConfig, 0, sizeof(spiConfig));
spiConfig.isLsbFirst
spiConfig.cpol
spiConfig.ssnPol
spiConfig.cpha
spiConfig.leadTime
spiConfig.lagTime
spiConfig.ssnCtrl
spiConfig.clock
=
=
=
=
=
=
=
=
CyFalse;
CyTrue;
CyFalse;
CyTrue;
CY_U3P_SPI_SSN_LAG_LEAD_HALF_CLK;
CY_U3P_SPI_SSN_LAG_LEAD_HALF_CLK;
CY_U3P_SPI_SSN_CTRL_FW;
25000000; /* Maximum value of SPI clock is 33
spiConfig.wordLen
= 8;
MHz*/
apiRetStatus = CyU3PSpiSetConfig (&spiConfig, NULL);
3.3.2
GPIO Configuration
The GPIO module is initialized and configured with the help of the following code. GPIO 52 and GPIO 50 are
configured as inputs so that GPIO 52 can be used to monitor the INIT_B pin and GPIO 50 can be used to monitor the
DONE signal coming from the Xilinx FPGA. You can find this piece of code in the function
CyFxConfigFpgaApplnInit()present in the file cyfxconfigfpga.c.
/* Init the GPIO module */
gpioClock
.fastClkDiv = 2;
gpioClock.slowClkDiv = 0;
gpioClock.simpleDiv = CY_U3P_GPIO_SIMPLE_DIV_BY_2;
gpioClock.clkSrc = CY_U3P_SYS_CLK;
gpioClock.halfDiv = 0;
apiRetStatus = CyU3PGpioInit(&gpioClock, NULL);
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
/* Configure GPIO 52 as input */
gpioConfig.outValue = CyTrue;
gpioConfig.inputEn = CyTrue;
gpioConfig.driveLowEn = CyFalse;
gpioConfig.driveHighEn = CyFalse;
gpioConfig.intrMode = CY_U3P_GPIO_INTR_BOTH_EDGE;
apiRetStatus = CyU3PGpioSetSimpleConfig(FPGA_INIT_B, &gpioConfig);
/* Configure GPIO 50 as input */
apiRetStatus = CyU3PGpioSetSimpleConfig(FPGA_DONE, &gpioConfig);
3.3.3
DMA Channel Creation to Set Up the Data Transfer
The DMA Manual channel is created between the producer USB socket and the consumer CPU socket so that the
configuration data that has been received on the Bulk out endpoint (0x01) of FX3 can be directed manually to the SPI
module. The code that helps to create a DMA Manual channel is as follows. You can find this piece of code in the
function CyFxConfigFpgaApplnStart()present in the file cyfxconfigfpga.c.
/* Create a DMA MANUAL channel for U2CPU transfer. The DMA size is set
based on the USB speed. */
dmaCfg.size = size;
dmaCfg.count = CY_FX_SLFIFO_DMA_BUF_COUNT;
dmaCfg.prodSckId = CY_FX_PRODUCER_USB_SOCKET;
dmaCfg.consSckId = CY_U3P_CPU_SOCKET_CONS;
dmaCfg.dmaMode = CY_U3P_DMA_MODE_BYTE;
/* Enabling the callback for produce event. */
dmaCfg.notification = 0;
dmaCfg.cb = NULL;
dmaCfg.prodHeader = 0;
dmaCfg.prodFooter = 0;
dmaCfg.consHeader = 0;
dmaCfg.prodAvailCount = 0;
apiRetStatus = CyU3PDmaChannelCreate
(&glChHandleUtoCPU,CY_U3P_DMA_TYPE_MANUAL_IN,
&dmaCfg);
3.3.4
Communication Between the FPGA Configuration Utility and FX3 Firmware
Two vendor commands are used to control the FX3 firmware functionality from the application that runs on the PC
FPGA Configuration Utility. The FX3 firmware sets the events based on the vendor commands that it receives. It sets
the event CY_FX_CONFIGFPGAAPP_START_EVENT for starting the FPGA configuration after it receives the
vendor command 0xB2 (VND_CMD_SLAVESER_CFGLOAD) along with the length of the configuration bit file. The
firmware also sets the event CY_FX_CONFIGFPGAAPP_SW_TO_SLFIFO_EVENT for switching to the Slave
FIFO interface after it receives the vendor command 0xB1 (VND_CMD_SLAVESER_CFGSTAT) and only if the
FPGA configuration is successful. The following piece of code is used to do this job. You can find this code in the
function CyFxSlFifoApplnUSBSetupCB () present in the file cyfxslfifosync.c.
if (bRequest == VND_CMD_SLAVESER_CFGLOAD)
{
if ((bReqType & 0x80) == 0)
{
CyU3PUsbGetEP0Data (wLength, glEp0Buffer, NULL);
filelen = uint32_t)(glEp0Buffer[3]<<24)|(glEp0Buffer[2]<<16)|
(glEp0Buffer[1]<<8)|glEp0Buffer[0];
glConfigDone = CyTrue;
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
/* Set CONFIGFPGAAPP_START_EVENT to start configuring FPGA */
CyU3PEventSet(&glFxConfigFpgaAppEvent,
CY_FX_CONFIGFPGAAPP_START_EVENT, CYU3P_EVENT_OR);
isHandled = CyTrue;
}
}
if (bRequest == VND_CMD_SLAVESER_CFGSTAT)
{
if ((bReqType & 0x80) == 0x80)
{
glEp0Buffer [0]= glConfigDone;
CyU3PUsbSendEP0Data (wLength, glEp0Buffer);
/* Switch to slaveFIFO interface when FPGA is configured successfully*/
if (glConfigDone)
CyU3PEventSet(&glFxConfigFpgaAppEvent,
CY_FX_CONFIGFPGAAPP_SW_TO_SLFIFO_EVENT,
CYU3P_EVENT_OR);
isHandled = CyTrue;
}
}
3.3.5
A c t i o n s B a s e d o n E ve n t s
The FX3 firmware continuously looks for the events mentioned previously and takes the actions corresponding to
those events. SlFifoAppThread_Entry() in cyfxslfifosync.c contains the following code.
/* Wait for events to configure FPGA */
txApiRetStatus = CyU3PEventGet (&glFxConfigFpgaAppEvent,
(CY_FX_CONFIGFPGAAPP_START_EVENT |
CY_FX_CONFIGFPGAAPP_SW_TO_SLFIFO_EVENT),
CYU3P_EVENT_OR_CLEAR, &eventFlag,
CYU3P_WAIT_FOREVER);
if (txApiRetStatus == CY_U3P_SUCCESS)
{
if (eventFlag & CY_FX_CONFIGFPGAAPP_START_EVENT)
{
/* Start configuring FPGA */
CyFxConfigFpga(filelen);
}
else if ((eventFlag & CY_FX_CONFIGFPGAAPP_SW_TO_SLFIFO_EVENT))
{
/* Switch to SlaveFIFO interface */
CyFxConfigFpgaApplnStop();
CyFxSwitchtoslFifo();
CyFxSlFifoApplnInit();
CyFxSlFifoApplnStart();
}
}
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
3.4
Slave Serial Interface Implementation
CyFxConfigFpga is the function that implements the Xilinx Slave Serial interface. To start the configuration
process, FX3 drives PROGRAM_B LOW. Then FX3 waits for INIT_B to go LOW, and it starts to clock the data when
INIT_B becomes HIGH again. After sending all configuration data to the FPGA, FX3 decides whether the
configuration is successful based on the DONE signal. The DONE signal will be set HIGH if the configuration is
successful. See Figure 1 for clarity on the timing diagram. You can find this function in cyfxconfigfpga.c.
/* This is the function that writes configuration data to the Xilinx FPGA
*/
CyU3PReturnStatus_t CyFxConfigFpga(uint32_t uiLen)
{
uint32_t uiIdx;
CyU3PReturnStatus_t apiRetStatus;
CyU3PDmaBuffer_t inBuf_p;
CyBool_t xFpga_Done, xFpga_Init_B;
/* Pull PROG_B line to reset FPGA */
apiRetStatus = CyU3PSpiSetSsnLine (CyFalse);
CyU3PGpioSimpleGetValue (FPGA_INIT_B, &xFpga_Init_B);
CyU3PGpioSimpleGetValue (FPGA_INIT_B, &xFpga_Init_B);
if (xFpga_Init_B)
{
glConfigDone = CyFalse;
return apiRetStatus;
}
CyU3PThreadSleep(10);
/* Release PROG_B line */
apiRetStatus |= CyU3PSpiSetSsnLine (CyTrue);
CyU3PThreadSleep(10);
// Allow FPGA to startup
/* Check if FPGA is now ready by testing the FPGA_Init_B signal */
apiRetStatus |= CyU3PGpioSimpleGetValue (FPGA_INIT_B, &xFpga_Init_B);
if( (xFpga_Init_B != CyTrue) || (apiRetStatus != CY_U3P_SUCCESS) ){
return apiRetStatus;
}
/* Start shifting out configuration data */
for(uiIdx = 0; (uiIdx < uiLen) && glIsApplnActive; uiIdx +=
uiPacketSize )
{
if(CyU3PDmaChannelGetBuffer (&glChHandleUtoCPU, &inBuf_p, 2000) !=
CY_U3P_SUCCESS){
glConfigDone = CyFalse;
apiRetStatus = CY_U3P_ERROR_TIMEOUT;
break;
}
apiRetStatus = CyU3PSpiTransmitWords(inBuf_p.buffer , uiPacketSize);
if (apiRetStatus != CY_U3P_SUCCESS)
{
glConfigDone = CyFalse;
break;
}
if(CyU3PDmaChannelDiscardBuffer (&glChHandleUtoCPU) !=
CY_U3P_SUCCESS)
{
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
glConfigDone = CyFalse;
apiRetStatus = CY_U3P_ERROR_TIMEOUT;
break;
}
}
CyU3PThreadSleep(1);
apiRetStatus |= CyU3PGpioSimpleGetValue (FPGA_DONE, &xFpga_Done);
if( (xFpga_Done != CyTrue) )
{
glConfigDone = CyFalse;
apiRetStatus = CY_U3P_ERROR_FAILURE;
}
return apiRetStatus;
}
3.5
Reconfiguring the I/O Matrix
The FPGA Configuration Utility sends the vendor command 0xB1 (VND_CMD_SLAVESER_CFGSTAT) automatically
after all the configuration data has been sent to FX3. FX3 firmware will switch to the Slave FIFO interface only if the
FPGA configuration is successful. The following piece of code is used to reconfigure the I/O matrix. This is not
necessary to do if the same I/O resources are used in the final application. However, in this case, the I/O matrix
needs to be reconfigured because the Slave FIFO firmware (taken from AN65974) uses the 32-bit interface on
GPIF II. Make sure that all the affected peripheral modules are deinitialized before reconfiguring the I/O matrix. In this
application, the GPIO and SPI modules are deinitialized before reconfiguring the I/O matrix. The I/O matrix
configuration needed to work as 32-bit Slave FIFO interface follows. Find this piece of code in the function
CyFxSwitchtoslFifo () present in the file cyfxslfifosync.c.
io_cfg.useUart
= CyTrue;
io_cfg.useI2C
= CyFalse;
io_cfg.useI2S
= CyFalse;
io_cfg.useSpi
= CyFalse;
#if (CY_FX_SLFIFO_GPIF_16_32BIT_CONF_SELECT == 0)
io_cfg.isDQ32Bit = CyFalse;
io_cfg.lppMode
= CY_U3P_IO_MATRIX_LPP_UART_ONLY;
#else
io_cfg.isDQ32Bit = CyTrue;
io_cfg.lppMode
= CY_U3P_IO_MATRIX_LPP_DEFAULT;
#endif
/* No GPIOs are enabled. */
io_cfg.gpioSimpleEn[0] = 0x00000000;
io_cfg.gpioSimpleEn[1] = 0;
io_cfg.gpioComplexEn[0] = 0;
io_cfg.gpioComplexEn[1] = 0;
status = CyU3PDeviceConfigureIOMatrix (&io_cfg);
3.5.1
Endpoint Configuration and Restoring the Sequence Number
The same producer endpoint (EP1 OUT BULK) is used for FPGA configuration and for transferring data from USB to
the FPGA connected to FX3 over the Slave FIFO interface after the FPGA configuration is successful. However, the
EP1 is reconfigured to enable burst transfers to support high-bandwidth data transfers after the Slave FIFO interface
is enabled. So the CyU3PSetEpConfig API is called twice for configuring the same endpoint. This API clears the
sequence number associated with the endpoint. Data transfers fail when the USB 3.0 Host and FX3 device find a
mismatch in the sequence number. Therefore, you need to restore the sequence number so that the USB 3.0 Host
can perform successful data transfers even after reconfiguring the EP1. This is valid only for USB 3.0 data transfers.
CyU3PUsbGetEpSeqNum API gets the current sequence number
CyU3PUsbSetEpSeqNum sets the active sequence number for an endpoint.
The
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an
endpoint,
and
10
Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
3.6
Integrating the Configuration Firmware into Your Design
This section explains how to integrate the configuration firmware into your design. See the project in the attachments
to this application note while you read the following steps.
1.
2.
3.
4.
5.
6.
7.
8.
3.7
Import the cyfxconfigfpga.c and cyfxconfigfpga.h files into your project.
Comment the main() function in your design because main() is implemented in cyfxconfigfpga.c.
Call CyFxConfigFpgaApplnInit() in the thread entry function in place of your application initialization
function.
In
this
example,
CyFxConfigFpgaApplnInit()
is
called
in
function
SlFifoAppThread_Entry() in place of CyFxSlFifoApplnInit().
Call CyFxConfigFpgaApplnStart() in the USB event callback function in place of your application start
function.
In
this
example,
CyFxConfigFpgaApplnStart()is
called
in
function
CyFxSlFifoApplnUSBEventCB in place of CyFxSlFifoApplnStart().
Comment out the piece of code that handles the USB enumeration part in CyFxSlFifoApplnInit() since
the CyFxConfigFpgaApplnInit() already handles it.
Add the support for vendor commands and events as they are implemented in this example.
The I/O matrix needs to be reconfigured if your application requires a different set of resources. In this example,
the I/O matrix reconfiguration code can be found in the function CyFxSwitchtoslFifo () in
cyfxslfifosync.c.
Change your application thread entry function similar to SlFifoAppThread_Entry().
Software Details
This section describes the host application and the USB 3.0 driver needed for running the project files attached to this
application note. Figure 5 shows the system-level block diagram including the Host application and drivers needed on
PC to configure the FPGA interfaced to FX3.
Figure 5. System-Level Block Diagram Showing Software Details on PC Side
After FPGA Configuration
is Done Successfully
PC
FPGA
Configuration
Utility
Cyusb3
.sys
USB
USB
Interface
Block
GPIF II
Configured
as Slave
FIFO
Interface
Bank
I/O
Bank
I/O
FX3
FPGA
Configuration
I/Os (SPI
Lines and
Few GPIOs)
Rest of the User’s
System
Config
I/O
During
Configuration
3.7.1
Host Application
The FPGA Configuration Utility is developed specifically for this application and is available as an attachment.
USB Driver: cyusb3.inf and cyusb3.sys are part of the EZ-USB FX3 SDK.
www.cypress.com
Document No. 001-84868 Rev. *C
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
An example host application, the FPGA Configuration Utility, created for configuring the FPGA is included in the
design. The application is developed in Visual C# 2008 Express Edition using the Cypress Application Development
Library CyUSB.dll, which is included in the Cypress SuperSpeed USBSuite. The device must be bound to
CyUSB3.sys, a general-purpose driver developed by Cypress. The Host application provided with this application
note serves as a reference for developing an FPGA Configuration Utility. It provides an option to download the
firmware image into FX3 RAM and the flexibility to select the bitstream (.bin) file for Xilinx FPGA configuration. In
addition, this application gives the status of each step and shows the next step to run the demo successfully. Figure 6
shows an FPGA Configuration Utility elements annotation.
Figure 6. FPGA Configuration Utility Elements Annotation
1: Downloads the firmware image into FX3 RAM
2: Selects the configuration file for the Xilinx FPGA (.bin file)
3: Downloads the selected configuration file over FX3
4: Displays the status of each step during the configuration of the Xilinx FPGA
5: Displays the next step
4
Operating Instructions
This section shows you how to configure the Xilinx FPGA connected to the FX3 SuperSpeed Explorer Kit with the
help of software and firmware projects that are attached to this application note. Make the hardware connections
between the Xilinx Spartan-6 SP601 Evaluation Kit and the FX3 SuperSpeed Explorer Kit (or FX3 DVK), as Table 3
shows. These connections are the same as the ones shown in the hardware interconnection diagram (Figure 2). In
addition, connect the FX3 SuperSpeed Explorer Kit (or FX3 DVK) to the Xilinx Spartan-6 SP601 Evaluation Kit with
the help of the Samtec-to-FMC connector. Note that the hardware setup used for this application note is the same as
the one used in AN65974, but you need five wires to connect the signals required to configure the FPGA.
Table 3. Hardware Connections Between Xilinx SP601 Evaluation Kit and FX3 Explorer Kit (or FX3 DVK)
Pin Placement on FX3
SuperSpeed Explorer Kit
Signal Name
Pin Placement on SP601 Evaluation Kit
PROGRAM_B
Pin 1 of J12
Pin 23 of J7
Pin 5 of J34
INIT_B
One end of resistor R90 (as shown in
Figure 7)
Pin 31 of J7
Pin 6 of J20
CCLK
Pin 7 of J12
Pin 27 of J7
Pin 3 of J34
DIN
Pin 6 of J12
Pin 19 of J7
Pin 4 of J34
DONE
One end of R113 or LED DS9 (as shown
in Figure 7)
Pin 37 of J7
Pin 4 of J20
www.cypress.com
Document No. 001-84868 Rev. *C
Pin Placement on FX3 DVK
12
Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
Figure 7 Hardware Connections on Xilinx SP601 Evaluation Kit
1.
2.
3.
Run Template.exe present in the folder FPGA_Config_Utility\bin\Debug and see the utility that appears on the
screen. The following status message appears: No EZ-USB FX3 device is connected.
Connect the EZ-USB FX3 Explorer Kit or a FX3 DVK to a PC using a USB cable, as Figure 8 shows. Then
observe the status message EZ-USB FX3 Bootloader device connected that appears in the text box, as Figure
9 shows.
Click the Download Firmware button to download the firmware image into FX3 RAM and browse to the location
of the ConfigFpgaSlaveFifoSync.img file, as Figure 10 shows. Then click Open.
Figure 8. FPGA Configuration Utility When No EZ-USB FX3 Device Is Connected
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Document No. 001-84868 Rev. *C
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
Figure 9. FPGA Configuration Utility After Connecting the EZ-USB FX3 DVK to PC
Figure 10. Selecting the FX3 Firmware Image
The following status messages appear, as Figure 11 shows:
Programming RAM of Cypress EZ-USB FX3 BootLoader…….
Programming Succeeded
FX3 – Xilinx Slave Serial Programmer detected
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Document No. 001-84868 Rev. *C
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
Figure 11. FPGA Configuration Utility After Image File is Downloaded into FX3 RAM
4.
As the message is appearing on the utility, click the Select Bitstream button to select the .bin file for the FPGA.
If the .bin file is not available and you have only the .bit file, then convert the .bit to .bin by using the PromGen
command line. Alternatively, you can use the iMPACT PROM File Formatter to create a .bin for a Xilinx PROM.
Visit www.xilinx.com/support.html to get support on generating the .bin file.
5.
Browse to the location of the fpga_master.bin file, as Figure 12 shows. Click Open.
Figure 12. Selecting the Configuration Bit File (.bin) for the Xilinx FPGA
www.cypress.com
Document No. 001-84868 Rev. *C
15
Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
6.
Click the Configure button to configure the Xilinx FPGA, as shown in Figure 13. If the FPGA is configured
successfully, then the FX3 firmware switches to the Slave FIFO interface. The following status messages
appear, as Figure 14 shows.
Writing data to FPGA
Configuration data has been sent to FPGA
Configurations Successful
FX3 Slave FIFO interface is activated
Figure 13. FPGA Configuration Utility After Selecting the .bin File
Figure 14. FPGA Configuration Utility After FPGA Configuration Is Done Successfully
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Document No. 001-84868 Rev. *C
16
Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
You can observe the DS9 LED glowing on the Xilinx FPGA board after the configuration is successful. It does not
glow if something goes wrong during configuration. Figure 15 shows the DS9 LED glowing.
Figure 15. Hardware Setup After FPGA Is Configured Successfully
7.
Use the Control Center application to verify the loopback operation between FX3 and the Xilinx FPGA. Go to
Bulk out endpoint (0x01) and click the Transfer File-OUT button to transfer a file called TEST.txt, which is
located in the same folder. Then you can see the series A5 A5 A5 A5 5A 5A 5A 5A get transmitted successfully
to the Bulk out endpoint, as Figure 16 shows.
Figure 16. USB Control Center After Transferring TEST.txt File Over Bulk Out Endpoint
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Document No. 001-84868 Rev. *C
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
8.
Select Bulk in endpoint and click Transfer Data-IN. Observe that the received data is the same as the data that
has been transmitted to the Bulk out endpoint, as Figure 17 shows. The data path is as follows: Control
Center > Bulk out endpoint of FX3 > FPGA reads the data from Bulk out endpoint > FPGA writes the
same data to Bulk in endpoint of FX3 > Control Center.
Figure 17. USB Control Center After Data-IN to Get Data From Bulk in Endpoint
5
Summary
This application note demonstrated a solution for efficiently configuring a Xilinx FPGA over USB using Cypress FX3.
You can integrate this solution into a system in which an FPGA acts as an interface with FX3 for USB 3.0
functionality, eliminating the need for a dedicated programming circuit to configure the FPGA.
6
Associated Project Files
Table 4 describes the files attached to this application note.
Table 4. Description of Files in the Attachment
Folder name
Description
FPGA Configuration Utility
Source code of the PC-side application
FX3 firmware
Source code of the FX3 firmware
fpga_write
Source code of Xilinx FPGA acting as a master device. This is same as the FPGA code available
with AN65974.
bin
It contains the following files:
TEST.txt—Data file that can be used to test the loopback operation between FX3 and FPGA.
ConfigFpgaSlaveFifoSync.img—Image file of FX3 firmware.
Template.exe—Executable file of FPGA Configuration Utility.
www.cypress.com
Document No. 001-84868 Rev. *C
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
7
References
CYUSB3014 datasheet
Getting Started with FX3
FX3 Slave FIFO Interface
Spartan-6 Generation Configuration User Guide – Xilinx UG380
Xilinx Spartan-6 FPGA SP601 Evaluation Kit
Using a Microprocessor to Configure Xilinx FPGAs via Slave Serial or SelectMAP Mode
About the Author
Name:
Rama Sai Krishna
Title:
Application Engineer Staff
www.cypress.com
Document No. 001-84868 Rev. *C
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Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
Document History
®
Document Title: AN84868 - Configuring an FPGA Over USB Using Cypress EZ-USB FX3™
Document Number: 001-84868
Revision
ECN
Orig. of
Change
Submission
Date
Description of Change
**
3883306
RSKV
01/25/2013
New application note.
*A
4399551
RSKV
06/05/2014
Provided link for FPGA configuration guide in the introduction section.
Updated Table 2.
Updated “Reconfiguring the I/O Matrix” section.
Added “Endpoint Configuration and Restoring the Sequence Number” section.
Added Table 3 to list the hardware connections between the Xilinx SP601
Evaluation Kit and the FX3 DVK.
*B
4660848
AMDK
02/13/2015
Updated firmware to work in release build
Added link to SuperSpeed USB code examples
Sunset Review
*C
4909562
MDDD
12/21/2015
Fixed broken links
Updated Figure based on new FX3 Explorer Kit
Added connection information in Table 3 for FX3 Explorer Kit
Updated template
www.cypress.com
Document No. 001-84868 Rev. *C
20
Configuring an FPGA Over USB Using Cypress EZ-USB® FX3™
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© Cypress Semiconductor Corporation, 2013-2015. The information contained herein is subject to change without notice. Cypress Semiconductor
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Document No. 001-84868 Rev. *C
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