<< Chapter < Page Chapter >> Page >

Do not use an asterisk in front of ARx variables here, since this is not indirect addressing.

Examples:

mvmm AR3,AR5 ; sets AR5 = AR3 stm #5,AR2 ; sets AR2 = 5 ldm AR0,A ; sets A = AR0

Immediate addressing: #k3, #k5, k, #k9, #lk

Immediate addressing means that the numerical value of the data is itself provided within the assemblyinstruction. Various TMS320C54x instructions allow immediate data of 3, 5, 8, 9, or 16 bits in length, which are signifiedin the assembly language syntax descriptions with one of the above symbols. The 16-bit form is the most common and issignified by #lk . 16-bit immediate values always require an extra instruction word and therefore take an extramachine cycle to execute.

An immediate data operand is almost always specified in assembler syntax by prepending a pound sign ( # ) to the data. Depending on the context, the assembler mayassume that you meant immediate addressing anyway.

Examples:

ld #0,A ; sets A = 0 cmpm AR1,#1 ; sets flag TC = 1 if AR1 == 1; else TC = 0

Labels make this more complicated. Recall that a label in your assembly code is nothing more than shorthand for thememory address where the labeled code or data is stored. So does an instruction like

stm coef,AR2 ; sets AR2 = memory address of label coef

mean to store the contents of memory location coef in AR2 , or does it mean to store the memory address coef itself in AR2 ? The second interpretation is correct. Because the stm instruction has only one form, expecting a #lk immediate operand, the assembler does not care whether the label is prefixed with a pound signor not. Still, it would have been better for us to include the pound sign in the above example for clarity.

Many instructions have several versions allowing the use of different addressing modes (see ld for a good example of this). With these instructions, including thepound sign is not optional when specifying immediate addressing. The only safe rule, then, is always to prefix thelabel with a pound sign if you wish to specify the memory address of the label and not the contents of that address.

If you are not sure how a particular instruction has been assembled, you can always examine the .lst file produced by the assembler, and compare the hexadecimal opcodeslisted to the left of the assembly instructions with the assembly opcodes given in the assembly language manual(Chapter 4 of the Mnemonic Instruction Set reference).

Direct addressing: smem and others

In the modes called direct addressing by TI, the instruction opcode contains a memory offset (see the "dma"bits on page 5-8 of the CPU and Peripherals reference) seven bits long, which is combined with either the DP (data pointer) or SP (stack pointer) register to obtain a complete 16-bit data-memory address. This divides the data memory intopages of 128 words each.

Questions & Answers

anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
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
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
Difference between extinct and extici spicies
Amanpreet Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Dsp laboratory with ti tms320c54x. OpenStax CNX. Jan 22, 2004 Download for free at http://cnx.org/content/col10078/1.2
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Dsp laboratory with ti tms320c54x' conversation and receive update notifications?

Ask