Monday, March 19, 2018

lab record

TECHNICAL SPECIFICATIONS of LPC1768

(15-16 of ARMCTXM3)

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INTRODUCTION TO KEIL:

One of the important part in making an embedded system is loading the software/program developed into the microcontroller. Usually it is called “burning software” into the controller.

Prerequisite operations with the program that must be done before “burning a program” into a controller, This includes writing the program in assembly language or C language in a text editor like notepad, compiling the program in a compiler and finally generating the hex code from the compiled program.

Earlier people used different softwares/applications for all these 3 tasks.

a.Writing was done in a text editor like notepad/wordpad,

b. compiling was done using a separate software (probably a dedicated compiler for a particular controller like 8051),

c. converting the assembly code to hex code was done using another software etc.

It takes lot of time and work to do all these separately, especially when the task involves lots of error debugging and reworking on the source code.

Keil MicroVision is a free software which solves many of the pain points for an embedded program developer. This software is an integrated development environment (IDE), which integrated a text editor to write programs, a compiler and it will convert your source code to hex files too.

Keil was founded in 1982 by Günter and Reinhard Keil, initially as a German GbR. In April 1985 the company was converted to Keil Elektronik GmbH to market add-on products for the development tools provided by many of the silicon vendors. Keil implemented the first Ccompiler designed from the ground-up specifically for the 8051 microcontroller.

Keil provides a broad range of development tools like ANSI C compiler, macro assemblers, debuggers and simulators, linkers, IDE, library managers, real-time operating systems and evaluation boards for Intel 8051, Intel MCS-251and ARM families.

In October 2005, Keil (Keil Elektronik GmbH in Munich, Germany, and Keil Software, Inc. in Plano, Texas) were acquired by ARM.

PROJECT CREATION IN KEIL UVISION:

(24-29 of ARMCTXM3)

INTRODUCTION TO FLASH MAGIC:

Flash Magic is Windows software from the Embedded Systems Academy that allows easy access to all the ISP features provided by the devices. These features include

☞Erasing the Flash memory (individual blocks or the whole device)

☞Programming the Flash memory

☞Modifying the Boot Vector and Status Byte

☞Reading Flash memory

☞Performing a blank check on a section of Flash memory

☞Reading the signature bytes

☞Reading and writing the security bits

☞Direct load of a new baud rate (high speed communications)

☞Sending commands to place device in Boot loader mode

Flash Magic provides a clear and simple user interface to these features. Under Windows, only one application may have access the COM Port at any one time, preventing other applications from using the COM Port.

Flash Magic only obtains access to the selected COM Port when ISP operations are being performed. This means that other applications that need to use the COM Port, such as debugging tools, may be used while Flash Magic is loaded.

FLASH PROGRAMMING STEPS:

(30 OF ARMCTXM3)

Thursday, February 22, 2018

Text Books

Text 1:
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Text 2:
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Sunday, February 18, 2018

video

1. how to install keil uvision5?

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2. how to setup keil uvision5 IDE environment before writing the C program?

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Wednesday, February 14, 2018

LPC1768: Register Configuration (lpc17xx.h)

Outcome:
At the end of this Student will be familiar with the lpc17xx GPIO and SFR registers and how to access them and configure them.

General Purpose Input Output is what let’s microcontroller be something more than a weak auxiliary processor. With GPIOs MCU can interact with the physical world, connecting up other devices and turning microcontroller into something useful.

LPC1768 Memory Map

As it is 32-bit architecture it can access 2^32 locations(4GB).
This 4Gb of addressable locations are divided into ROM, RAM, GPIO, AHB Peripherals as shown in the below image.
In LPC1768 the GPIO registers are mapped to memory location 0x2009 C000 - 0x2009 FFFF.

Register Configuration

LPC1768 has its GPIOs divided into five ports PORT0 - PORT4, although many of them are not physically 32bit wide.

The Below registers will be used for Configuring and using the GPIOs registers for sending and receiving the Digital signals.

Lets consider 100 pin LPC1768 as an example.

Pins on LPC1768 are divided into 5 groups (PORTs) starting from 0 to 4.

Pin naming convention: Px.y

Ex: P0.0 (group 0, pin 0) or (port 0, pin 0).

Each pin has 4 operating modes:

GPIO(default), 1st alternate function, 2nd alternate function, 3rd alternate function.

Details about the configuration of GPIO port pins.

1. Pin Function Setting

The LPC_PINCON register controls the operating mode of these pins.

Bit Value	Function
00	GPIO Function
01	1^st alternate function
10	2^nd alternate function
11	3^rd alternate function

Example:
To set pin 0.3 as GPIO (set corresponding bit to 00)
LPC_PINCON –> PINSEL0 &= ~ ((1<<7) | (1<<6));

To set pin 0.3 as ADC channel 0.6 (2^nd alternate function, set corresponding bit to 10)
LPC_PINCON –> PINSEL0 &= ((1<<7) | (0<<6)); // you may omit (0<<6)
For reference follow [Page No: 108, Table: 79]

2. Pin Direction Setting

Register LPC_GPIOn –> FIODIR [31:0] control the pin input/output, where ‘n’ stands for pin group (0-4). To set a pin as output, set the corresponding bit to ‘1’. To set a pin as input, set the corresponding bit to ‘0’, by default, all pins are set as input (all bits are 0).
Example:
To set 0.3 as output
LPC_GPIO –> FIODIR |= (1<<3);

3. Pin is Set as Output

A pin digital high/low setting
LPC_GPIOn –> FIOSET is used to turn a pin to HIGH. Register LPC_GPIOn –> FIOCLR is used to turn a pin to low. To turn a pin to digital ‘1’ (high), set the corresponding bit of LPC_GPIOn –> FIOSET to 1. To turn a pin to digital ‘0’ (low), set the corresponding bit of LPC_GPIOn –> FIOCLR to 1.

Example
Turn Pin 0.3 to high
LPC_GPIO0 –> FIOSET |= (1<<3);
If we set LPC_GPIOn –> FIOSET bit to ‘0’ there is no effect.
Turn Pin 0.3 to low
LPC_GPIO0 –> FIOCLR |= (1<<3);
If we set LPC_GPIOn –> FIOCLR bit to ‘0’ there is no effect.

4. Pin is Set to Input

Read a Pin Value
Register LPC_GPIOn –> FIOPIN stores the current pin state. The corresponding bit is ‘1’ indicates that the pin is driven high.

Example
To read current state of Pin 0.3
Value = ((LPC_GPIO0 –> FIOPIN & (1<<3)) >> 3);
Note: write 1/0 to corresponding bit in LPC_GPIOn –> FIOPIN can change the output of the pin to 1/0 but it is not recommended. We should use LPC_GPIOn –> FIOSET and GPIOn –> FIOCLR instead.

Pin Internal Pull up Setting
Register LPC_PINCON –> PINMODEn is used to set up a pin internal pull-up.
LPC_PINCON –> PINMODE0 [1:0] control P0.0 internal pull-up
…..
LPC_PINCON –> PINMODE0 [31:30] control P0.15 internal pull-up,
Please see LPC_PINCON –> PINSELn for the full list [Page No: 114].

Bit Value	Pin Mode
00	On chip pull-up resistor enabled
01	Repeater Mode
10	Tri-State mode, (neither pull-up nor pull-down)
11	On chip pull-down resistor enabled

Example:
By default all pins which are set as input has internal pull-up on (00).
To disable internal pull-up on pin 0.3
LPC_PINCON –> PINMOD0 |= (1<<7);