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Data rate usci_b (master)

The system clock is configured to operate with a frequency of ~ 1048 kHz from the DCO. This frequency will be the working base frequency of the USCI module. The connection operates at a clock frequency of ~ 95.3 kHz:

// DATA RATE // data rate ->fSCL = SMCLK/11 = 95.3kHz UCB0BR0 = 0x0B; // fSCL = SMCLK/11 = 95.3kHzUCB0BR1 = 0x00;

Port configuration usci_b (master)

In order to set the external interfaces at the USCI module, it is necessary to configure the I/O ports. Select the USCI peripheral in I 2 C mode matching the connections provided at the Experimenter’s board:

P3SEL |=0x06; // Assign I2C pins to USCI_B0

Usi (slave) control registers configuration

The connection via I 2 C bus will operate in the following mode:

- Slave mode;

- USI counter interrupt enable (RX and TX);

- START condition interrupt-enable;

- USIIFG is not cleared automatically.

The following control registers are configured based on these characteristics:

USICTL0 = 0XC1;//USICTL0 = USIPE7 | USIPE6 | USIPE5 | USILSB | USIMST | USIGE | USIOE | USISWRST //USIPE7 (USI SDI/SDA port enable) = 1b ->USI enabled //USIPE6 (USI SDO/SCL port enable) = 1b ->USI enabled //USIPE5 (USI SCLK port enable) = 0b ->SCLK disable //USILSB (LSB first) = 0b ->MSB first //USIMST (Master) = 0b ->Slave mode //USIGE (Output latch control) = 0b ->Output latch // enable depends on shift clock//USIOE (Serial data output enable) = 0b ->Output enable //USISWRST (USI software reset) = 1b ->Software resetUSICTL1 = 0x70;//USICTL1 = USICKPH | USII2C | USISTTIE | USIIE | USIAL | USISTP | USISTTIFG | USIIFG //USICKPH (Clock phase select) = 0b ->Data is changed // on the first SCLK edge and captured on the following edge.//USII2C (I2C mode enable) = 1b ->I2C mode enabled //USISTTIE = 1b ->Interrupt on START condition enabled //USIIE = 1b ->USI counter interrupt enable //USIAL (Arbitration lost) = 0b ->Not used //USISTP (STOP condition received) = 0b ->Not used //USISTTIFG (START condition int. flag) = 0b ->Not used //USIIFG (USI counter int. flag) = 0b ->No int. pending

The slave unit interrupt service routine is not complete. The portion related to the “I2C_TX” state needs to be completed:

- Configure the USI module as output;

- Insert the information to transmit using the transmission register;

- Configure the bit counter.

// USI Bit Counter Register USICNT |= 0x20;//USICNT = USISCLREL | USI16B | USIIFGCC | USICNTx//USISCLREL (SCL release) = 0b ->SCL line is held low // if USIIFG is set//USI16B (16-bit shift register enable) = 0b ->8-bit // shift register mode//USIIFGCC (USI int. flag clear control) = 1b ->USIIFG // is not cleared automatically//USICNTx (USI bit count) = 00000b ->(not relevant)// I2C state machine: USICTL0 |= USIOE; // SDA = outputUSISRL = SlaveData; // Send data byte USICNT |= 0x08; // Bit counter = 8, TX data

Analysis of operation

Once the USCI module is configured in accordance with the previous steps, initiate the experiment with the files ( Lab3_Comm_1.c ) (master – MSP430FG4618) and ( Lab3_Comm_2.c ) (slave – MSP430F2013), compiling them and running them on the Experimenter’s board.

For this laboratory, the following jumper settings are required:

- PWR1/2, BATT, LCL1/2, JP2;

- SPI: H1- 1&2, 3&4.

The slave data is sent and increments from 0x00 with each transmitted byte, which is verified by the Master. The LED is off for address or data Acknowledge and the LED turns on for address or data Not Acknowledge. LED3 blinks at each data request. It is turned on with a START condition and it is turned off by the data transmit acknowledge by the slave (Note: the I 2 C bus is not released by the master since the successive START conditions are interpreted as “repeated START”).

Verify the value received setting a breakpoint in the line of code “ RxBuffer = UCB0RXBUF; ” of the USCI interrupt.

This example and many others are available on the MSP430 Teaching ROM.

Request this ROM, and our other Teaching Materials here (External Link)

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
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
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
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
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
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
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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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