arm-usb-tiny Vs. arm-usb-tiny-h and OpenOCD libusb Vs ftdi?

Development Boards MicroMod
1

I have both a arm-usb-tiny and an arm-usb-tiny-h. I’m trying to get the high speed out of the h device. I ran the same openocd script file on the same device running the same application (not much more than blinking an LED and has a microsecond timer). The script file simply reads the memory address of the timer multiple times. (mdw)

arm-usb-tiny

uses FTDI drivers

uses version Open On-Chip Debugger 1.0 (2008-10-04-10:00)

could read a memory address repeatedly around 2ms timing

arm-usb-tiny-h

uses libusb0 drivers

uses version Open On-Chip Debugger 0.3.0 (2009-11-07-14:18)

could read a memory address repeatedly around 4ms timing

In the last day I’ve read quite abit about the D2xx and FTDI and its still confusing to me. I THINK this is the situation:

likely my old OpenOCD used the ftdi driivers and that the “new” openocd I’m running (from Olimex CD) uses this libusb which is slower?

I THINK the fix is to compile my own version of OpenOCD using the ftdi drivers, and then maybe I can finally experience the “high” speed?

config files are very similar (except for deprecated commands) and both devices successfully poll, halt, resume, etc.

Any thoughts?

2

Hi

just succeeded in selecting the ( windows) FTDI drivers for olimex. Using openocd 0.4. Works well. don’t know the difference with the LIBusb drivers because i could not getting it work.

succes

Dig

3

I Uninstalled the libusb drivers, forced it to use the same ones as ARM-USB-Tiny, then ran the same (old) OpenOCD and got the timing back to the 2ms per memory read. So far “high” speed is elusive.

4

Hello All,

I posted the following in another thread. Item 4 explains the driver differences (as I understand them).

I am at a similiar stage getting OpenOCD to work with an Olimex ARM-USB-Tiny-H. (I have not used this device before - more of an AVR fan in the past)

There are a few things you might find useful

  1. Correct device VID & PID (from my .cfg file)

REFERENCE: http://www.olimex.com/dev/arm-usb-tiny.html

interface ft2232

ft2232_device_desc “Olimex OpenOCD JTAG TINY”

ft2232_layout “olimex-jtag”

ft2232_vid_pid 0x15BA 0x002a

Note the PIDs could be 0003 0004 as well - you can use USBviewer.exe to get this info.

  1. I am using version OpenOCD 0.3.0. The commands and their syntax changes significantly between OpenOCD version releases. Be aware!

  2. Speed - try slow

ft2232_latency 10

jtag_khz 200

jtag_speed is the command format for older versions of OpenOCD. should be Clk speed/200khz (between 30 and 150??)

Note the addition of latency (in ms). Should be between 2 and 10. Not certain if available in version 0.1.0

  1. Reset Configuration

No idea what your board has. SRST and TRST may be available separately.

I use

reset_config trst_and_srst separate

jtag_ntrst_delay 200

jtag_nsrst_delay 200

Note delay parameters (ms) - some boards need resets help for a short time to work.

  1. Drivers

Almost certainly the real problem.

Need to know if 32-bit or 64-bit OS. The Olimex drivers are only for 32-bit. If you are using 64-bit OS then Olimex say to use FTDI 64-bit drivers. However the FTDI website drivers are only certified for FTDI chip VID & PIDs. So cannot install on Vista as if wants certified drivers.

There are versions of FTDI drivers with correct hardware VID & PIDs (which I have just found/loaded).

See http://www.olimex.com/dev/index.html Software Item 2. (The Crossworks FTD2xx drivers)

Having said all of the above and now trying these last FTD2xx drivers…

I am still getting “unable to open FTDI device: Device not found” error.

I am about to try a Windows XP 64-bit and Windows XP 32-bit OS to see if I can get around the problem.

I would appreciate any help I can get.

Based on other posts it seems you do not need to set any latency and jtag_khz can be set as high as 1500 without problems. Hope this helps you.

Ernest