HC08-QTQY Development Board

December, 2008
This is a simple development board I built based around the Freescale M68HC08 Family of 8-bit microcontroller units (MCUs), specifically the HC08QT and HC08QY MCU. There are many like it on the market as Freescale and various other 3rd party companies offer something like it. But this is mine, I made it, I understand it and I like it. Plus I designed it for my specific needs. I wanted to be able to rapidly prototype various design ideas involving a simple 8-bit microcontroller. This board makes it easy to pull it from the shelf, write some code, burn it, run it then stand back and experience the sweet smell of success or smoke...whichever happens.
The HC08-QTQY Development Board I designed was built to support either the standard 16-pin MON08 Debug interface or the more simplified, User Monitor based MON08 UART Debug Interface. These options are described completely in Freescale's Application Note AN2317. I typically use the P&E Microsystems USB Multilink debugger along with the Freescale Code Warrior Development Suite (Special Version) with this board. I have had no problems and they work well together. There are obviously many other development and debugging options, but this is what I have used that works well for me.
The HC08-QT/QY MCU variations are quite interesting because they are offered in low-pin count (8-pin and 16-pin respectively) and decent amount of FLASH (1k-4k) to do something useful. This makes them suitable for all kinds of small microcontroller projects. These microcontrollers are typically available for less than $3 a piece depending on the options.
The following are the features of this HC08-QTQY Development Board.
  • Supports the Freescale HC08Q MCU Family with 16-pin or 8-pin configurations. The HC08Q Family is a member of the low-cost, high-performance M68HC08 Family of 8-bit microcontroller units (MCUs). The M68HC08 Family is a Complex Instruction Set Computer (CISC) with a Von Neumann architecture. All MCUs in the family use the enhanced M68HC08 central processor unit (CPU08) and are available with a variety of modules, memory sizes and types, and package types.
  • Processor Specific Features are;
    • High-Performance M68HC08 Architecture
    • Up to 8.2-MHz internal bus frequency
    • Up to 4 Kbytes of on-chip FLASH memory (QT/QY)
    • Up to 512 bytes of on-chip RAM
    • Analog to digital converter
    • Up to 16-bit, 2-channel timer interface module (TIM)
    • Trimmable internal oscillator
    • Up to 14 input/output (I/O) Pins (QT/QY)
  • Standard 16-Pin MON08 Interface for various low cost debuggers
  • 20-pin male header with breakout of all MCU signals
  • Sockets for 8-pin and 16-pin DIPs
  • Spare +5VDC and GND pins.
  • Push-buttons for RESET and IRQ.
  • RS-232 Half and Full Duplex Support via TTL serial converter.
  • DB-9 Serial Connector with full breakout male header.
  • Power LED indicator and switch
  • Status LED indicator which may be connected to an general purpose output pin. This LED is driven by a small transistor.
  • Power connector header (Molex)
  • User configurable dip-switches to allow connecting or disconnecting various MON08 signals.
This is a description of each of the dip-switches on the HC08-QTQY Development Board. The dip-switches provide a convenient way to disengage various MON08 and Development Board signals from the processor without having to disconnect the MON08 cable.
Below is a layout diagram of the 8-position dip-switch on this board.
Links / Downloads
Click on the hyperlinks below to download schematics, PDFs and EagleCad project files. You can also use the Mouser and BatchPCB links to order your own parts and boards if you like.
Schematics: .pdf, EagleCad(.sch)
PCB Layout: EagleCad(.brd), Assembly Guide (.pdf)
Gerbers (.zip)
Software (.zip) - This is an example test CodeWarrior project which simply toggles the STATUS Led on pin PTB7 every 100msec and prints the short banner to the serial port connected to PTB6. This example project is currently configured for the HC08QY (16-pin) MCU but can be easy adapted to the HC08QT (8-pin) MCU by changing the output pins. For this test code to work properly with the HC08QY the jumpers on the development board must match those shown in the photo above.
Mouser EZ-Buy Project (Parts) - Not complete yet
BatchPCB Order Link (PCB)