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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

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
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Akash Reply
it is a goid question and i want to know the answer as well
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characteristics of micro business
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for teaching engĺish at school how nano technology help us
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Do somebody tell me a best nano engineering book for beginners?
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there is no specific books for beginners but there is book called principle of nanotechnology
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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
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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 ?
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What is lattice structure?
s. Reply
of graphene you mean?
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or in general
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in general
s.
Graphene has a hexagonal structure
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I start with an easy one. carbon nanotubes woven into a long filament like a string
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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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