The 68HC11 (6811 or HC11 for short) is a microcontroller (µC) family originally from Motorola, now produced by Freescale Semiconductor, descended from the Motorola 6800 microprocessor. A microcontroller (also MCU or µC is a functional Computer system-on-a- chip. Freescale Semiconductor Inc is an American Semiconductor manufacturer The 6800 is an 8-bit Microprocessor produced by Motorola and released shortly after the Intel 8080 in late 1974 A microprocessor incorporates most or all of the functions of a Central processing unit (CPU on a single Integrated It is a CISC microcontroller. A complex instruction set computer ( CISC, pronounced like " sisk " is a Microprocessor Instruction set architecture (ISA in which The 68HC11 devices are more powerful and more expensive than the 68HC05 microcontrollers, and are used in barcode readers, hotel card key writers, amateur robotics, and various other embedded systems. The 68HC08 ( HC08 in short is a broad family of 8-bit Microcontrollers from Freescale Semiconductor (formerly Motorola Semiconductor A bar code (also barcode) is an optical Machine-readable representation of data An embedded system is a special-purpose Computer system designed to perform one or a few dedicated functions often with Real-time computing constraints
Internally, the HC11 instruction set is upward compatible with the 6800, with the addition of a Y index register. An instruction set is a list of all the instructions and all their variations that a processor can execute The 6800 is an 8-bit Microprocessor produced by Motorola and released shortly after the Intel 8080 in late 1974 An index register in a computer's CPU is a Processor register used for modifying Operand addresses during the run of a program typically for doing vector/ (Instructions using the Y register have opcodes prefixed with the byte 0x18). In computer technology an opcode ( op eration code) is the portion of a Machine language instruction that specifies the operation to be performed In Mathematics and Computer science, hexadecimal (also base -, hexa, or hex) is a Numeral system with a It has two eight-bit accumulators, A and B, two sixteen-bit index registers, X and Y, a condition code register, a 16-bit stack pointer, and a program counter. Eight-bit CPUs normally use an 8-bit data bus and a 16-bit address bus which means that their Address space is limited to 64 KBs This is not a "natural In a Computer 's central processing unit ( CPU) an accumulator is a register in which intermediate arithmetic and logic results are stored An index register in a computer's CPU is a Processor register used for modifying Operand addresses during the run of a program typically for doing vector/ In Computer science, a stack is an Abstract data type and Data structure based on the principle of Last In First Out (LIFO The program counter, or shorter PC (also called the instruction pointer, part of the instruction sequencer in some Computers is a register in In addition, some instructions treat the A and B registers as a combined 16-bit D register.
The standard bootloader for the HC11 family is called BUFFALO, "Bit User Fast Friendly Aid to Logical Operation" (a BUFFALO prompt seen on the serial port at bootup is a sign that a board's flash memory has been erased).
Different versions of the HC11 have different numbers of external ports, labeled alphabetically. The most common version has five ports, A, B, C, D, and E, but some have as few as 3 ports (version D3). Each port is eight-bits wide except for D, which is six bits (in some variations of the chip, D also has eight bits). It can be operated with an internal program and RAM (1 to 768 bytes) or an external memory of up to 64 kilobytes. A kilobyte (derived from the SI prefix Kilo -, meaning 1000 is a unit of Information or Computer storage equal to either 1024 With external memory, B and C are used as address and data bus. An address bus is a Computer bus, controlled by CPUs or DMA -capable Peripherals for specifying the Physical addresses of computer In Computer architecture, a bus is a subsystem that transfers data between computer components inside a Computer or between computers In this mode, port C is multiplexed to carry both the lower byte of the address and data. Time-Division Multiplexing ( TDM) is a type of Digital or (rarely analog Multiplexing in which two or more signals or bit streams are transferred
A MC68HC24 port replacement unit is available for the HC11. When placed on the external address bus, it replicates the original functions of B and C. Port A has input capture, output compare, pulse accumulator, and other timer functions; port D has serial I/O, and port E has an analog to digital converter (ADC). An analog-to-digital converter (abbreviated ADC, A/D or A to D) is an electronic integrated circuit which converts continuous signals to
The popular Handy Board robotics controller by Fred Martin is based on the 68HC11. The Handy Board is a popular handheld robotics controller The Handy Board was developed at MIT by Fred G
The Freescale 68HC12 is an enhanced version of the 68HC11. The 68HC12 (6812 or HC12 for short is a 16-bit Microcontroller family from Freescale Semiconductor.
The Freescale 68HC16 microcontroller is intended as a 16-bit mostly software compatible upgrade of the 68HC11. The 68HC16 (it s also abbreviated as HC16 is a highly modular Microcontroller family based on the CPU16 16-bit core made by Freescale Semiconductor (formerly known
This article was originally based on material from the Free On-line Dictionary of Computing, which is licensed under the GFDL. The Free On-line Dictionary of Computing ( FOLDOC) is an online searchable encyclopedic Dictionary of Computing subjects The GNU Free Documentation License ( GNU FDL or simply GFDL) is a Copyleft License for free documentation designed by the Free Software