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Central processing unit (msp430x cpu)

Main features of the msp430x cpu architecture

The MSP430X CPU extends the addressing capabilities of the MSP430 family beyond 64 kB to 1 MB. To achieve this, there are some changes to the addressing modes and two new types of instructions. One type of new instructions allows access to the entire address space, and the other is designed for address calculations.

The MSP430X CPU address bus is 20 bits, but the data bus is still 16 bits. The CPU supports 8-bit, 16-bit and 20-bit memory accesses. Despite these changes, the MSP430X CPU remains compatible with the MSP430 CPU, having a similar number of registers. A block diagram of the MSP430X CPU is shown in the figure below:

Msp430x cpu block diagram.

Although the MSP430X CPU structure is similar to that of the MSP430 CPU, there are some differences that will now be discussed.

With the exception of the status register SR, all MSP430X registers are 20 bits. The CPU can now process 20-bit or 16-bit data.

Msp430x cpu registers

R0 (pc) - program counter

Has the same function as the MSP430 CPU, although now it has 20 bits.

R1 (sp) - stack pointer

Has the same function as the MSP430 CPU, although now it has 20 bits.

R2 (sr) - status register

Has the same function as the MSP430 CPU, but still only has 16 bits.

Description of the sr bits.

R2 (cg1) and r3 (cg2) - constant generators

The registers R2 and R3 can be used to generate six different constants commonly used in programming, without the need to add an extra 16-bit word of code to the instruction. The constants below are chosen based on the bit (As) of the instruction that selects the addressing mode.

Values of constant generators.

Whenever the operand is one of these six constants, the registers are selected automatically. Therefore, when used in constant mode, registers R2 and R3 cannot be addressed explicitly by acting as source registers.

R4-r15 – general-purpose registers

These registers have the same function as the MSP430 CPU, although they now have 20 bits. They can store 8-bit, 16-bit or 20-bit data. Any byte written to one of these registers clears bits 19:8. Any word written to one of these registers clears bits 19:16. The exception to this rule is the instruction SXT, which extends the sign value to fill the 20-bit register.

The following figures illustrate how the operations are conducted for the exchange of information between memory and registers, for the following formats: byte (8 bits), word (16 bits) and address (20 bits).

The following figure illustrates the handling of a byte (8 bits) using the suffix .B.

Example: register-byte/byte-register operation.

The following figure illustrates the handling of a word (16-bit) using the suffix .W.

Example: register-word/word-register operation.

Example: register-word/word-register operation.

The following figure illustrates the manipulation of an address (20 bits) using the suffix .A.

Example: register - address-word operation.

Example: address-word - register operation.

Request the MSP430 Teaching ROM Materials here (External Link)

Questions & Answers

what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
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
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
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.
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
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
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
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
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
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.
what is the actual application of fullerenes nowadays?
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.
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Source:  OpenStax, Teaching and classroom laboratories based on the “ez430” and "experimenter's board" msp430 microcontroller platforms and code composer essentials. OpenStax CNX. May 19, 2009 Download for free at http://cnx.org/content/col10706/1.3
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