FX2 - an attempt with USB 2.0
A PCB (160 mm x 100 mm) for experimenting with the
Cypress EZ-USB FX2 USB 2.0 Chip
This IC contains a complete USB 2.0 interface with 480 Mbit/s throughput,
a comfortable FIFO with a controller (state machine),
but is hard to use due to its very small housing and pitch.
This chip, CY7C68013-128 TQFP, is used to have an option for external memory.
Mostly, for debugging.
This PCB is only two-sided and hand-madeable vias, therefore, any hobbyist
with UV lamp and etching fluid can make this.
Possible uses of this board are:
For accessing most drawings you need
GhostView and GhostScript.
- USB scope probe with extreme sample depth
- IDE device adaptor
- Fast data transport from a 19" rack to PC and vice versa.
PCB foil is made for positive laquer.
Größenvergleich.jpg 04-Dez-2004 22:19 23K Photo
Heiß aufs Löten.jpg 14-Feb-2004 02:49 39K Photo
USB-Festplatte.jpg 24-Aug-2004 10:54 52K Photo
adc2usb.zip 18-Dez-2004 17:46 41K [view]
ads8402.png 18-Dez-2004 17:08 33K
cypress.zip 10-Dez-2004 23:04 324K [view]
fx2.zip 19-Mar-2006 22:07 127K Eagle [Einsicht]
fx2.psz 11-Feb-2005 21:33 91K Als PDF
oben.jpg 17-Dez-2004 19:19 82K Photo
unten.jpg 17-Dez-2004 19:16 84K Photo
Who want to make such a PCB too?
Answer since 1 year: one or two
...was made in Eagle according to the Cypress reference design
Due to lack of FPGA/CPLD (??) there are no LEDs, but that's the only
disadvantage I have found.
RAM, ATA connector, RS232, and port expander PCF8574 are compatible.
All FX2 signals are available on an ERNI connector for 19" racks.
For the scope probe, an A/D converter is spared.
Schematic Part 1: ICs
Please click onto images to view the schematics!
Last change: The LM317LZ was not sufficient as linear regulator;
instead, a simple solution with zener diode and transistor is used.
Schematic Part 2: Connectors
...you should bring it to work step by step.
Partial placed components, top side
You can place both 1206 and 0805 shaped SMD resistors and capacitors.
Please populate step by step and test the board!
Detail view: hand-soldered 128 pin chip
Plug this card on your PC. If it reports an error, check the following:
- Vias, check them
- FX2 IC, check every pin for contact and no short circuit
- USB receptacle, el.cap, transistor, res, zener diode
- Crystal and 22 pF caps
- 2 caps 100 nF and R?? (10 kΩ)
- Reset circuitry (100 kΩ, 100 nF)
- I²C pullups
Then you give the Windows popup dialog the EZUSBW2K.INF from Cypress
development kit. Then start EzMr.exe and check if the device is found.
- 3,3 V on every supply pin
- 0 V on every ground pin
- work of oscillator
- connection of "important" wires for USB, crystal, reset, bus control, and I²C
Recognition of high-speed mode is possible by inspecting pipe sizes
of more than 64 Bytes for bulk transfer.
You may now populate the PCB. I advise to place the IDE connector and
some R/C and LED "DASP" (Drive Active / Slave Present) around
to check connection to a hard disk.
Check it using following procedure:
The firmware is active to the USB side ONLY if it detects a hard disk!!
The HDD LED (»DASP«) must light on shortly, then you get an USB hard drive.
In Windows 98 you need another driver:
- Plug EEPROM-Jumper and then connect the PCB to your PC
- Start of "EZ-USB Control Panel", set to FX2,
- press Button , give the file "fx2_ata.iic", wait about. 30 seconds!
- disconnect, connect, or let renumerate pressing another button
Connection with IDE hard drive(It works! Really!)
example firmware stated above
controls following peripherals:
That example firmware polls for USB "interrupts" in its main loop.
(Much better than writing interrupt service routines!)
All requests, inclusive String Descriptors, are handled,
inclusive two Alternate Settings.
- 2 channel A/D converter 16bit ADS8402 with 1 MSa/s
as "oscilloscope" or "transient recorder" with direct
data transfer to PC, see schematic.
- 1 channel D/A converter 16bit
TDA1543 with 48 kSa/s
as fine-tuneable sine generator (both frequency and amplitude)
The GPIF (General Purpose InterFace), a programable state machine,
works without decision points, but
in "long transfer mode", whereby count of
bytes to transfer are kept permanently to 4 GB.
FX2 throttles automatically when FIFO is full.
The FIFO is 4x buffered. The block size is a tad large than necessary,
to prevent sample jitter.
From time to time there are not-acknowledged transfers (NAK).
The Bulk transfer is available for USB compatibility reasons.
In high-speed mode, a large interrupt transfer ist implemented too.
|Alternate Setting||Full Speed (12 Mbit/s)||High Speed (480 Mbit/s)
|0, EP2:||Bulk, 64 Byte Packets||Bulk, 512 Byte Packets
|1, EP2:||Isochronous, 1020 Byte per frame||Isochronous, 512 Byte per microframe
|2, EP2:||not available||Interrupt, 512 Byte per microframe
|Sample rate||250 kSa/s (USB maximum)||1 MSa/s (about ADU maximum)
|Netto data rate||1000 kByte/s (1000 Byte per frame)||4000 kByte/s (500 Byte per microframe)
There is one multi-function yellow LED. It lights permanently while USB is
configured and not sleeping. It flashes slowly while EP0 transfer
and faster while EP2 (main data) transfer.
An additional (blue or green) LED lights up when operating in high-speed mode
and flashes on USB errors.
When viewing the
source code, you will wonder about missing interrupt service routines.
This ist intended and the same as Cypress does.
Cypress simply sets a bit in its ISR and polls that bit in a main loop.
For such stupid operation, you need no ISR at all!
When you program the EEPROM, and your system crashes meanwhile,
you may result in a crashing 8051 firmware.
Then, you cannot start the board with plugged jumper, and for accessing the
EEPROM with EzMr.EXE, you need a 2-byte-adressed EEPROM on FX2
startup! (Bit ID1 in I2CS @0xE678 set).
How you can delete at least the first Byte of EEPROM without
pulling the chip out and into an external programmer? The right way:
MAKROS.I51 make the source code more readable when accessing XRAM.
Register R0 (not DPTR!) will be used for adressing;
MPAGE is fixed to 7Eh.
Two symbolic parameters
allow faster access to adjanced bytes in XRAM.
Unfortunalely, all FX2 chips are about same in size:
- Pull jumper JP1,
- Plug board to PC,
- Start "EZ-USB Control Panel", set to FX2,
- Plug jumper JP1,
- Press button , load "vend_ax\vend_ax.hex"
(this is a Cypress firmware, enabling some other Vendor Requests),
- Fill the line :
- Req: 0xA9 (undocumented Read/Write access to 2-Byte EEPROM),
- Value: 0 (= start address),
- Index: 0xBEEF (= ignore that value),
- Length: 1 (= length of data to write),
- Dir: 0 OUT (data writing Vendor Request;
you may read with 1 IN your EEPROM content),
- Hex Bytes: FF (= data, delete first byte C0 or C2),
- Press button ,
- Check your board by pulling and plugging to PC.
Size comparison of packages on 5 mm grid paper
Up to Rund um den PC.
Chemnitz, Wednesday, 10-Apr-2013 19:01:01 CEST