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.