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Examples:

hold .word 1 ; reserve one word of storage and initialize to 1 count .word 0 ; reserve one word of storage and initialize to 0 . . . . ld *(count),B ; sets B = 0 (assuming memory was not changed) st T,*(hold) ; sets (storage location at address hold) = T

Indirect addressing: smem, xmem, ymem

Indirect addressing on the TMS320C54x always uses the auxiliary registers AR0 through AR7 and comes in two basic flavors. These are easily recognized from the assembly language syntaxdescriptions as either Smem or Xmem/Ymem .

Smem

In Smem indirect addressing, only one indirect address is used in the instruction and a number ofvariations is possible (see the table on page 5-13 of the CPU and Peripherals reference). An asterisk is always used, which signifies indirect addressing. Any of theregisters AR0 - AR7 may be used, with optional modifications: automatic post-decrement byone, pre- and post-increment by one, post-increment and post-decrement by n ( n being stored in AR0 ), and more, including many options for circular addressing (which automaticallyimplements circular buffers) and bit-reversed addressing (which is useful for FFTs).

Xmem/ymem

Xmem/Ymem indirect addressing is generally used in instructions that need two different indirect addresses,although there are a few instances where an Xmem by itself is specified in order to save bits in the opcode for other options. In Xmem/Ymem indirect addressing, fewer bits are used to encode the option modifiers in the opcode; hence,fewer options are available: post-increment by one, post-decrement by one, and post-increment by AR0 with circular addressing.

Examples:

stl B,*AR6 ; sets (contents of location pointed to by AR6) = low word of B stl B,*AR6+0% ; sets (contents of location pointed to by AR6) = low word of B, ; then increments AR6 with circular addressing mar *+AR3(-6) ; decrements AR3 by 6 (increment by -6)

The mar (modify address register) instruction is unusual in the sense that it takes an Smem operand but does nothing with the data pointed to by the ARx register. Its purpose is to perform any of the allowed register modifications discussed abovewithout having to do anything else. This is often handy when you are using an Xmem/Ymem -type instruction but need to do an ARx modification that is only allowed with an Smem -type operand.

Summary

The ld instruction is illustrative of the many possible addressing modes which can be selected with theproper choice of assembly language syntax:

ld #0,A ; immediate data: sets A = 0 ld 0,A ; DP-referenced direct: sets A = (contents of the address DP + 0) ld mydata,A ; DP-referenced direct: sets A = (contents of the address ; DP + lower seven bits of mydata) ld #mydata,A ; immediate data: sets A = 16 bit address mydata ld *(mydata),A ; *(lk) direct: sets A = (contents of the 16 bit address mydata) ld B,A ; accumulator: sets A = B ld *AR1+,A ; indirect: sets A = (contents of address pointed to by AR1), ; and afterwards increments AR1 by one ldm AR2,A ; memory-mapped register: sets A = AR2

Questions & Answers

I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
How can I make nanorobot?
Lily
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Ece 320 - spring 2003. OpenStax CNX. Jan 22, 2004 Download for free at http://cnx.org/content/col10096/1.2
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