Hi Martin & Karan
karan wrote:
i have always used external + jtag power supply without any problem.
and you should use it, otherwise, when the led will blink,
you will notice that the lcd loses power with the same timing.
r u able to reprogram the board?
i remember reading something about fuses on the msp430.
that the user code is protected, and to reporgram it,
you have to pass the correct password.
Two different things: The password is only used with the bootstrap
loader used via a UART interface.
To Blow the fuse you need 6V up to 7V to TDI/TCLK with a current of
100mA for at least 1mS. Since you don't provide any external power
supply it is impossible to blow the fuse by mistake (provided Olimex
haven't shipped a target with a blown fuse).
I've never seen this very message but also have faced somewhat strange
problems accessing my msp. Chris Liechti wrote once (in fact he wrote it
a couple of times in different thereads :-) that most of these problems
are due to power suppliance aspects with targets only driven by JTAG
without external supply --> AND HE WAS RIGHT (Thanx Chris for your
hints: I can erase with "jumpered on board battery"; strange way but it
works). I mailed to Olimex and asked them for electrical specification
or at least the current the parport-JTAG connector can provide. This is
what they answered:
MSP430-JTAG takes power from LPT port
different computers have different capabilities
notebooks, desktop etc
so the max current will depend on your LPT port capability, but it's not
more than 2-3 mA
Olimex
This means if the JTAG provides 3V the msp consumes in active mode
470mA-570mA with 1MHz which p.e. also means using a board driven at 8MHz
exceeds the JTAG's capabilities (max. 6MHz results in less than 3mA).
So providing some additional power could be worthwhile anyway (though as
Chris already wrote: Some care has to be taken!).
and once the fuse is blown the code on the processor is not accessible
to anyone
(this is used for final productions of msp430 + some company's
proprietery software)
so that no one can steal the code.
but in this case, you should not be able to reprogram the board,
As far as I know the fuse only protects the JTAG interface. After
blowing the fuse access is still possible using the bootstrap loader via
a UART. In this case the "evil proprietary software company ;°)" can use
the 256-bit password to access the bootstrap loader and so even can
reprogram it.
Best regards
Arnd-Hendrik
and should get the error everytime, instead of intermittently.
hope it helps.
karan
CM II
Resolution Systems Inc.
On Wed, 2004-09-29 at 01:30, Collins Martin (ext) wrote:
/Hi,
i get the error message:
error: msp430:Could not access device - security fuse is blown (30)
from gdb-proxy intermittently. I downloaded and installed msp-gcc just
last week so I've got the latest versions.
I'm using the MSP430-449STK2 <//_http://www.olimex.com/dev/msp-449stk2.html_>
kit from Olimex. I'm not providing
an external power supply to avoid the problems associated with the JTAG
interface
having different levels to the rest of the board.
As I said I see the problem every now and then. I just wondered if someone knows
what it's about?
Thanks for any info,
Martin.
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