> I think you mistakes. By "immediate addressing" TI means many things,
> for example
> 1. ld #num,A - the immediate-addressed number num is included in
> the instruction opcode
> 2. ld *(x),A - the immediate-addressed address x is included in the
> instruction opcode.
> So, I think that by saying "dmad is using immediate addressing" TI
> support means that 7 offset bits are included in the instruction opcode.
> As to Chapter 5, "Volume 1: CPU and Peripherals" - the quotes in my
> original question are from there.
> Now, combining the kind comments of Jeff Brower, answer of TI's
> support and my own experiments I would define dmad addressing as follows:
> dmad is the direct data-memory addressing mode with 7 offset bits
> put into instruction opcode and segment 9 bits assumed zero.
> Any objection?
dmad --> data memory address
dmad specified as additional 16-bit bit instruction word
CPL and DP are ignored
Examples that use extra 16-bit instruction word to specify the dmad:
MVDM *(0x1234), AR3
MVDK *AR1, *(0x4567)
-Jeff > --- In , Micah Caudle <micah_caudle@y...> wrote:
> > They lied to you. dmad is used in Absolute Addressing
> > not in Immediate Addressing. And, furthermore,
> > immediate addressing does not have anything to do with
> > DP, CPL or SP anyway. The DP, CPL and SP stuff is
> > involved in Direct Addressing. Everything you need to
> > know is located in Chapter 5, "Volume 1: CPU and
> > Peripherals" document spru131G.
> > Hope that helps,
> > Micah
> > > Message: 2
> > > Date: Thu, 03 Jun 2004 14:06:57 -0000
> > > From: "Ilya Druker" <ied1970r@h...>
> > > Subject: 'dmad' - fundamental question to
> > > specialists
> > >
> > > Gentlemen,
> > >
> > > I am desperately looking for answer to the question
> > > what is 'dmad'
> > > addressing mode? The TI's materials don't give an
> > > intelligible
> > > definition but only foggiest discriptions like
> > > "16-bits immediate data
> > > memory address (0<=dmad<e535)" or "uses a specific
> > > value to specify
> > > and address in data space" or "the syntax for dmad
> > > uses a symbol or a
> > > number to specify an address in data space" etc. I
> > > dared to ask TI's
> > > support and their answer was:
> > >
> > > "dmad is using immediate addressing.
> > > In C54x TI terminology, immediate addressing is a
> > > "fixed" address
> > > composed of 2 "halves".
> > > 7-bits contained within the instruction's opcode
> > > 9-bits contained in the the DP (Data-memory page
> > > Pointer) register"
> > >
> > > It seems wrong as in the following example all 16
> > > bits were put by
> > > compiler to the opcode of the instruction (to remind
> > > - the syntax is
> > > "MVDM dmad,MMR"):
> > > MVDM *(33000),AR3
> > >
> > > Moreover, I don't see any difference in the
> > > performance under
> > > different environment conditions:
> > > 1. MVDM AR2,AR3 ; when CPL=0 and DP=0
> > > 2. MVDM AR2,AR3 ; when CPL=0 and DP!=0
> > > 3. MVDM AR2,AR3 ; when CPL=1 and DP=0
> > > 4. MVDM AR2,AR3 ; when CPL=1 and DP!=0
> > > 5. MVDM *(AR2),AR3
> > > It seems that DSP just ignores DP when the mode is
> > > dmad. If it is so
> > > why do we need MVMM for copying content of one
> > > register to another if
> > > we can use MVDM for that: instead of
> > > MVMM AR2,AR3
> > > use
> > > MVDM AR2,AR3
> > > or
> > > MVMD AR2,AR3 ?
> > >
> > > Can somebody make an order in this mess? I would
> > > really appreciate a
> > > competent answer or a reference.
> > >
> > > Thank you,
> > > Ilya Druker
Re: Re: 'dmad' - fundamental question to specialists
Started by ●June 7, 2004
Reply by ●June 8, 20042004-06-08