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The 68HC08 (HC08 in short) is a broad family of 8-bit microcontrollers originally from Motorola Semiconductor, later from Freescale Semiconductor. HC08's are fully code-compatible with their predecessors, the Motorola 68HC05.Like all Motorola processors that share lineage from the 6800, they use the von Neumann architecture as well as memory-mapped I/O. This family has five CPU registers. Apr 29, 2011 Entire AVR programmer has been build with using common parts and fits in the case of the serial connector. The socket pcb has been created to fit a 28-DIP AVR ATmega8 microcontroller, but you can build a socket pcb for any other AVR microcontroller out there.
(Redirected from Freescale 68HC08)
The 68HC08 (HC08 in short) is a broad family of 8-bitmicrocontrollers originally from Motorola Semiconductor, later from Freescale Semiconductor.
HC08's are fully code-compatible with their predecessors, the Motorola 68HC05. Like all Motorola processors that share lineage from the 6800, they use the von Neumann architecture as well as memory-mapped I/O. This family has five CPU registers 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 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 connectivity to USB 1.1. A typical and general purpose device from the HC08 family of units is the microcontroller M68HC908GP32.
The Freescale RS08 core is a simplified, 'reduced-resource' version of the HC08.
The Freescale HCS08 core is the next generation of the same processors.
External links[edit]
- M68HC08 Family Reference Manual - archive.org
Retrieved from 'https://en.wikipedia.org/w/index.php?title=Motorola_68HC08&oldid=931854022'
Eagle files and gerbers for a programmer designed for Microchip's series of AVR microcontrollers.
Overview
Microchip's series of AVR chips are simple 8 bit microcontrollers often used in Arduino boards. This programmer board can be used to program fuses and flash for bare AVR chips.
Features
- Compatible with USBASP firmware and features, including slow clock.
- Selectable target voltage of 3.3v, 5v, or target provided (1.8v - 5.5v).
- Built-in serial to USB converter.
- Board can remain connected to target after programming.
- USB-C interface to PC with full ESD and overload protection.
Design
This board is based on the hardware design for USBASP and is 100% compatible wth the USBASP firmware. I designed it to support different target voltages (namely 3.3v) and wanted built-in serial IO so I could connect a single connector to boards I design.
The board shows up as two USB devices: a FTDI serial port and a USBASP programmer. There is an on-board USB hub that exposes both devices. Target voltage is selectable through the VTARG switch and has three values:
- 5V (left): Provide 5 volts as power and logic levels to the target board.
- Float (middle): Adapt to whatever voltage the target board is using.
- 3.3V (right): Provide 3.3 volts as power and logic levels to the target board.
![Avr programmer software Avr programmer software](/uploads/1/2/6/4/126469795/250539521.jpg)
If your board provides voltage of its own make sure you keep VTARG in the middle position.
The different voltage levels are shifted through an array of level shifters. This circuit will change direction of the signals if PGM is bridged, which allows for initial programming of the board. All connections other than TXD and RXD also go to a high-impedance state whenever the red programming light is off (I reuse that signal line so I don't need any modifications to the USBASP firmware). Signal direction and tri-state is controlled by discrete logic, again so no USBASP mods are needed. The level shifters I'm using go to high-impedance state when VCCA or VCCB is grounded. This is handled by a push-pull pair of mosfets driven by discrete logic.
Programming
Once the board is complete it must be flashed with the USBASP code. You need another working programmer for this.
- Bridge the PGM pins on the board and set VTARG to either 5v or 3.3v depending on the output voltage of your existing programmer.
- Connect your existing programmer's connector to the board.
- Set your programmer to use a slow clock.
- Run 'make Makefile88 fuses' from the USBASP project.
- You can now turn off the slow clock feature of your programmer.
- Run 'make Makefile88' to flash the firmware.
If successful, a green LED should be lit on the board. This LED is controlled by the USBASP firmware so it's a good indicator everything's working. Remove the bridge to PGM and you should be good to go.