30-03-2012, 04:22 PM
MICROCONTROLLERS
Embedded-Systems-training-report.doc (Size: 744.5 KB / Downloads: 56)
Introduction
Circumstances that we find ourselves in today in the field of microcontrollers had their beginnings in the development of technology of integrated circuits. This development has made it possible to store hundreds of thousands of transistors into one chip. That was a prerequisite for production of microprocessors, and the first computers were made by adding external peripherals such as memory, input-output lines, timers and other. Further increasing of the volume of the package resulted in creation of integrated circuits. These integrated circuits contained both processor and peripherals. That is how the first chip containing a microcomputer, or what would later be known as a microcontroller came about.
Definition of a Microcontroller
Microcontroller, as the name suggests, are small controllers. They are like single chip computers that are often embedded into other systems to function as processing/controlling unit. For example, the remote control you are using probably has microcontrollers inside that do decoding and other controlling functions. They are also used in automobiles, washing machines, microwave ovens, toys ... etc, where automation is needed.
RAM ARCHITECTURE
The 8051 has a bank of 128 bytes of Internal RAM. This Internal RAM is found on-chip on the 8051 so it is the fastest RAM available, and it is also the most flexible in terms of reading, writing, and modifying its contents. Internal RAM is volatile, so when the 8051 is reset this memory is cleared. The 128 bytes of internal ram is subdivided as shown on the memory map. The first 8 bytes (00h - 07h) are "register bank 0".
Register Banks :
The 8051 uses 8 "R" registers which are used in many of its instructions. These "R" registers are numbered from 0 through 7 (R0, R1, R2, R3, R4, R5, R6, and R7).These registers are generally used to assist in manipulating values and moving data from one memory location to another. The concept of register banks adds a great level of flexibility to the 8051.
Bit Memory:
The 8051, being a communication oriented microcontroller, gives the user the ability to access a number of bit variables. These variables may be either 1 or 0. There are 128 bit variables available to the user, numbered 00h through 7Fh. The user may make use of these variables with commands such as SETB and CLR. It is important to note that Bit Memory is really a part of Internal RAM. In fact, the 128 bit variables occupy the 16 bytes of Internal RAM from 20h through 2Fh.
Special Function Register (SFR) Memory:
Special Function Registers (SFRs) are areas of memory that control specific functionality of the 8051 processor. For example, four SFRs permit access to the 8051’s 32 input/output lines. Another SFR allows a program to read or write to the 8051’s serial port .SFR is a part of Internal Memory. This is not the case.
Embedded-Systems-training-report.doc (Size: 744.5 KB / Downloads: 56)
Introduction
Circumstances that we find ourselves in today in the field of microcontrollers had their beginnings in the development of technology of integrated circuits. This development has made it possible to store hundreds of thousands of transistors into one chip. That was a prerequisite for production of microprocessors, and the first computers were made by adding external peripherals such as memory, input-output lines, timers and other. Further increasing of the volume of the package resulted in creation of integrated circuits. These integrated circuits contained both processor and peripherals. That is how the first chip containing a microcomputer, or what would later be known as a microcontroller came about.
Definition of a Microcontroller
Microcontroller, as the name suggests, are small controllers. They are like single chip computers that are often embedded into other systems to function as processing/controlling unit. For example, the remote control you are using probably has microcontrollers inside that do decoding and other controlling functions. They are also used in automobiles, washing machines, microwave ovens, toys ... etc, where automation is needed.
RAM ARCHITECTURE
The 8051 has a bank of 128 bytes of Internal RAM. This Internal RAM is found on-chip on the 8051 so it is the fastest RAM available, and it is also the most flexible in terms of reading, writing, and modifying its contents. Internal RAM is volatile, so when the 8051 is reset this memory is cleared. The 128 bytes of internal ram is subdivided as shown on the memory map. The first 8 bytes (00h - 07h) are "register bank 0".
Register Banks :
The 8051 uses 8 "R" registers which are used in many of its instructions. These "R" registers are numbered from 0 through 7 (R0, R1, R2, R3, R4, R5, R6, and R7).These registers are generally used to assist in manipulating values and moving data from one memory location to another. The concept of register banks adds a great level of flexibility to the 8051.
Bit Memory:
The 8051, being a communication oriented microcontroller, gives the user the ability to access a number of bit variables. These variables may be either 1 or 0. There are 128 bit variables available to the user, numbered 00h through 7Fh. The user may make use of these variables with commands such as SETB and CLR. It is important to note that Bit Memory is really a part of Internal RAM. In fact, the 128 bit variables occupy the 16 bytes of Internal RAM from 20h through 2Fh.
Special Function Register (SFR) Memory:
Special Function Registers (SFRs) are areas of memory that control specific functionality of the 8051 processor. For example, four SFRs permit access to the 8051’s 32 input/output lines. Another SFR allows a program to read or write to the 8051’s serial port .SFR is a part of Internal Memory. This is not the case.