openocd-devel

[Openocd-development] Question on V850 from NEC

[Michel C. <mic...@gm...>]

A MIPS question for those who know. Is there a usefull debug module in
the NEC V850? I would think that it would have at least the standard
MIPS module.
Am I wrong to think that? According to NEC and IAR the only way to debug
is to use the minicube.

Michel

-- 
Tired of Microsoft's rebootive multitasking?
then it's time to upgrade to Linux.
http://home.comcast.net/~mcatudal

Re: [Openocd-development] Question on V850 from NEC

[Xiaofan C. <xia...@gm...>]

2009/5/25 Michel Catudal <mic...@gm...>:
>
> A MIPS question for those who know. Is there a usefull debug module in
> the NEC V850? I would think that it would have at least the standard
> MIPS module.
> Am I wrong to think that? According to NEC and IAR the only way to debug
> is to use the minicube.
>

I do not know much about V850. Are you suggesting that V850
and MIPS core have some relations? Google does not suggest
this...

-- 
Xiaofan http://mcuee.blogspot.com

Re: [Openocd-development] Question on V850 from NEC

[Duane E. <op...@du...>]

Michel Catudal wrote:
> A MIPS question for those who know. Is there a usefull debug module in
> the NEC V850? I would think that it would have at least the standard
> MIPS module.
> Am I wrong to think that? According to NEC and IAR the only way to debug
> is to use the minicube.
>
> Michel
>
>   

I doubt the V850 would ever be supported by openocd. Reason: Support for 
it in GCC is long dead (dormant?), along with support for it in GDB, 
those two things have to come first.

-Duane.

Re: [Openocd-development] Question on V850 from NEC

[Michel C. <mic...@gm...>]

Duane Ellis a écrit :
>
> I doubt the V850 would ever be supported by openocd. Reason: Support
> for it in GCC is long dead (dormant?), along with support for it in
> GDB, those two things have to come first.
>
> -Duane.
>
>
>
The V850E is the latest and the latest GCC is working relatively well
from my tests. I will test it with the minicube in a few weeks and make
some comparisions
with NEC and IAR. I created the binaries for V850E so I could learn more
about that device that I am seriously looking into using for a new design.
I I use it I will likely buy the NEC or IAR Compiler.

Support for it would require to use the minicube if I am not mistaken as
from my talks with NEC the debug part is there.
It would require some reverse engineering because I doubt very much that
NEC would release information on it.
This is a lot of work. I wasn't asking if there was support planned, I
was just curious about their N-WIRE interface and as to what is in the
processor.

Michel

-- 
Tired of Microsoft's rebootive multitasking?
then it's time to upgrade to Linux.
http://home.comcast.net/~mcatudal

Re: [Openocd-development] Question on V850 from NEC

[Michel C. <mic...@gm...>]

Xiaofan Chen a écrit :
> 2009/5/25 Michel Catudal <mic...@gm...>:
>   
>> A MIPS question for those who know. Is there a usefull debug module in
>> the NEC V850? I would think that it would have at least the standard
>> MIPS module.
>> Am I wrong to think that? According to NEC and IAR the only way to debug
>> is to use the minicube.
>>
>>     
>
> I do not know much about V850. Are you suggesting that V850
> and MIPS core have some relations? Google does not suggest
> this...
>
>   

It might not be or is derived from one. I asked the question because I
was told at one time by a salesman that it was a MIPS

That line might give the implication that it is some sort of mips device.

/usr/lib/gcc-lib/mips-linux-gnu/2.95.4/include/va-v850.h

But from this site it appears to be an NEC design

http://www.nec.co.jp/press/en/9708/2801.html

Their JTAG interface is called N-WIRE

Their devices are about the best I have seen as far as embedded devices
are. Look at the V850ES though for the current ones.


For interrupt access
An ARM7TDMI takes 24 cycles to get to an interrupt
A Cortex-M3 takes 12 cycles to get to an interrupt
A V850E takes 4 cycles to get to an interrupt

As far as speed, at 32Mhz V850E is close to twice the speed of a
Micronas ARM7TDMI at 48Mhz.

I had never thought about looking at these devices until we were forced
to do so by Micronas screwing us by discontinuing their ARM7TDMI flash
devices.
I am very impressed by their Dashboard (Cluster) and Body devices (2 to
6 CAN available and price is very good)

The NEC programmer is only $100 but it is serial. The debugging is
N-WIRE (JTAG) and requires a device for debugging ($250-$500). I was
wondering if anyone
is familiar with these processors internals to know if the internal
debugging module has enough so we could do some debugging without
needing the outside device.

Some devices can be bought at relatively low price for personal designs,
so it is not just for us in the automotive industry.
http://www.futureelectronics.com/en/Search.aspx?dsNav=Ntk:PartNumberSearch|V850|1|,Ny:True,Nea:True

They are well known for having good prices for small 8 bit devices

http://www.futureelectronics.com/en/Technologies/Product.aspx?ProductID=UPD78F9202MACACANEC2877710


Michel


-- 
Tired of Microsoft's rebootive multitasking?
then it's time to upgrade to Linux.
http://home.comcast.net/~mcatudal