Hi Laurent,
>/ They are two major troubles with the Altera USB Blaster :
/[...]
>/ So if you want to accelerate the Altera USB Blaster you have to queue
/>/ the commands in the API driver and then send a sequence of command to
/>/ the device.
/I realized that and I'm currently working on it. Also I have an idea
how to implement a speed reduction (sometimes the 3 MHz provided by
the blaster are too much).
It should be good to be able to reduce downto 4KHz (32Khz / 6 or 8) for
the startup of some ARM7 !
>/ 2. This one cannot be corrected/modified in the OpenOCD source ( Blaster
/>/ hardware issues):
/>/ A debug session of a ARM or ARM Cortex processor need to have control of
/>/ SRST (System Reset) and sometimes TRST (TAP Reset). The Altera USB
/>/ Blaster do not provide these signals by default and this will be a
/>/ potential source of error when connecting to your target.
/Well, the blaster does have 2 unused GPIOs which can be used for this.
I already implemented a command to assign these GPIOs to SRST and/or
TRST including also the possibility to use inverted logic
(nSRST/nTRST).
great to know ! This is a good point for Blaster ! doc doc doc ...
>/ Also, the RTCK (Return Clock) is not supported by the USB Blaster. The
/>/ RTCK is really important to have on ARM7tdmi-s or the newer Cortex-A9
/>/ (Ax) ... to name a few. The RTCK helps to synchronize the JTAG Emulator
/>/ with the target frequency.
/>/ The JTAG frequency of the Blaster is difficult to manage. It is OK for
/>/ programming a FPGA, but troubleshooting when debugging a ARM !
/At the moment it seems as it will work for my Cortex-M3, everything
beyond that does not bother me at the moment.
I think there is a possibility to include the RTCK feature, but this
would need a hardware mod to the blaster and maybe adaption of the
CPLD code. But as I said, this does not bother me right now :)
regards,
Felix
Regards,
Laurent
http://www.amontec.com
_______________________________________________
Openocd-development mailing list
Openocd-development@lists.berlios.de
https://lists.berlios.de/mailman/listinfo/openocd-development
