Farhad-
> I have just one board.
> As you know each flash has usually a manufacture ID and a device
> code. These ID and code can be achieved in two ways:
> High Voltage Method and software Command. In High Voltage method, you
> put 12v on one address bus (A9), and then read from an address whose
> least significant address is 0 or 1. In software command method, you
> follow a sequence to achieve them.
> I can get these Id and code with High Voltage method. However, I
> can't with software command method.
>
> With considering these facts I will be thankful if state your opinion.
So you must be doing this:
-disconnect Flash A9 from the DSP (did you design
a jumper for this addr line?)
-connect 12V to Flash A9
-run DSP code that reads Flash with low addr bit 0,
then reads Flash with low addr bit 1
Please confirm. If you at any point connected 12V to the DSP address line (or
other
chip) then there would be damage.
-Jeff
PS. Please post to the group, not to me.
> --- In c..., Jeff Brower wrote:
> >
> > Farhad-
> >
> > > I design a board including a TMS320VC5416 and an Am29LV160D
> (Delay 70ns)
> > > flash memory. I connect Data and Address buses of DSP to the flash
> > > directly and make control signals of flash with MSTRB#, and R/W#
> of DSP.
> > >
> > > I observe control signals, data and address buses of flash and
> all of
> > > them it seems are correct; However, I can't write in a specific
> position
> > > since when I read the position I get another meaningless value.
> > >
> > > For test I also try to read Device Code and Manufacture ID of the
> flash
> > > with AutoSelect command. However, I can't get correct value. To
> get sure
> > > that the flash is error-free, I read these ID and code with VID
> (12v)
> > > and they were correct.
> > >
> > > Now I am confusing why I can't access the flash correctly while
> its
> > > control signals, data and address buses are correct (their enable
> time is
> > > sufficient.) May be as clue, there is another problem. DS# of DSP
> is low
> > > always when there is an access to external memory while I expect
> it gets
> > > low only when a read or write instruction to external memory
> executes.
> >
> > If you have board #1 (your board with 5416) and it cannot read
> Flash, and you have
> > board #2 (VID) and it can read Flash, then why can't you compare
> both of those using
> > digital scope and find the difference? There must be some signal
> or line on the
> > Flash that is being treated differently.
> >
> > -Jeff
> >