The 68HC08 (HC08 in short) is a broad family of

8-bit In computer architecture, 8-bit integers or other data units are those that are 8 bits wide (1 octet). Also, 8-bit central processing unit (CPU) and arithmetic logic unit (ALU) architectures are those that are based on registers or data buses ...

microcontroller A microcontroller (MCU for ''microcontroller unit'', often also MC, UC, or μC) is a small computer on a single VLSI integrated circuit (IC) chip. A microcontroller contains one or more CPUs ( processor cores) along with memory and programmabl ...

s originally from

Motorola Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent public companies, Motorola ...

Semiconductor, later from

Freescale Semiconductor Freescale Semiconductor, Inc. was an American semiconductor manufacturer. It was created by the divestiture of the Semiconductor Products Sector of Motorola in 2004. Freescale focused their integrated circuit products on the automotive, em ...

. HC08's are fully code-compatible with their predecessors, the

Motorola 68HC05 The 68HC05 (HC05 in short) is a broad family of 8-bit microcontrollers from Freescale Semiconductor (formerly Motorola Semiconductor). Like all Motorola processors that share lineage from the 6800, they use the von Neumann architecture as well ...

. Like all Motorola processors that share lineage from the 6800, they use the

von Neumann architecture The von Neumann architecture — also known as the von Neumann model or Princeton architecture — is a computer architecture based on a 1945 description by John von Neumann, and by others, in the '' First Draft of a Report on the EDVAC''. T ...

as well as memory-mapped I/O. This family has five CPU

register Register or registration may refer to: Arts entertainment, and media Music * Register (music), the relative "height" or range of a note, melody, part, instrument, etc. * ''Register'', a 2017 album by Travis Miller * Registration (organ), th ...

s that are not part of the memory. One 8-bit accumulator A, a 16-bit index register H:X, a 16-bit stack pointer SP, a 16-bit

program counter The program counter (PC), commonly called the instruction pointer (IP) in Intel x86 and Itanium microprocessors, and sometimes called the instruction address register (IAR), the instruction counter, or just part of the instruction sequencer, i ...

PC, and an 8-bit condition code register CCR. Some instructions refer to the different bytes in the H:X index register independently. Among the HC08's there are dozens of processor families, each targeted to different embedded applications. Features and capabilities vary widely, from 8 to 64-pin processors, from

LIN Lin or LIN may refer to: People *Lin (surname) (normally ), a Chinese surname *Lin (surname) (normally 蔺), a Chinese surname *Lin (The King of Fighters), Lin (''The King of Fighters''), Chinese assassin character *Lin Chow Bang, character in Fat ...

connectivity to USB 1.1. A typical and general purpose device from the HC08 family of units is the microcontrolle
M68HC908GP32
The

Freescale RS08 RS08 is a family of 8-bit microcontrollers by NXP Semiconductors. Originally released by Freescale in 2006, the RS08 architecture is a reduced-resource version of the Freescale MC68HCS08 central processing unit (CPU), a member of the 6800 micropro ...

core is a simplified, "reduced-resource" version of the HC08. The Freescale HCS08 core is the next generation of the same processors.

External links

M68HC08 Family Reference Manual
- archive.org
HC08 Processor Families

Helium Open-Source RTOS for HCS08 MCUs

Digital Core Design 68HC08 - HDL IP Core

Example assembly language code written for ASM8

Educational material for the HC08
Motorola microcontrollers Freescale Semiconductor microcontrollers {{electronics-stub