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Nitron LCD Terminal

MON08 Programming and Debugging circuits

Nitron Oscillator trimming

AB32 Board

HC08 Flash programming

HCS08 Controller

HCS12 Controller

HC12 Welcome Kit


Zwobots Display






The MC68HC908AB32 is another Controller of the HC08 Family. It has lots of onchip perirherals and Memory. 32 K-Byte of Flash, 1 K-Byte RAM and 512 Byte EEPROM is the onchip memory. Two timer modules with 4 channels each, Programmable interrupt timer, SPI, RS232 and 8 A/D Channels with 8 Bit resolution are on the chip. There is a total of 51 I/O Ports, five of them can be configured for Keyboard wakeup interrupts. Some ports got integrated pullups. The MCU has a lot of pins and so it comes in a QFP64 package. With the samples of the MC68HC908AB32 controllers that I ordered from Freescale, I built a Board. I soldered the MCU on an adapter board, so that I can use it on a protoboard.

Soldering wasn´t as hard as I expected. Using some extra solder flux it was quite easy. Use very little solder tin. Solder wick is helpful if contacts are shortened or to remove excessive solder. The decoupling capacitors are soldered directly on the adapter for a shorter path to the supply pins. The rest is to connect all the pins. All 51 Portpins had to be connected to headers. Power supply, IRQ, Reset and Clocking. All in all it is quite easy. The conntroller is clocked with a 4,9152 MHz Quarz as described in the datasheet. The values for the capacitors are from the datasheet too. A RC-combination and a switch for the reset pin. The signals for monitormode are connected to a connector, so that I can use it with my programmer. The schematic is here, it is not so hard to build. I put a LED on the soard to see if power supply is connected. The board looks like this..

All portpins are connected to headers. There is some space left on the board that can be used for expansions just like an LCD or a voltage regulator.






   © 2005 by Eckhard Gosch •