Re: Re: 'dmad' - fundamental question to specialists | TMS320C54x

Ilya Druker- > 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<=65535)" 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

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Discussion Groups | TMS320C54x | Re: Re: 'dmad' - fundamental question to specialists

Re: Re: 'dmad' - fundamental question to specialists - Jeff Brower - Jun 7 19:38:00 2004

Re: 'dmad' - fundamental question to specialists - Ilya Druker - Jun 8 4:42:00 2004