There are projects where it would be really nice to be able to utilize one of the newest high integration 8051 derivatives in a project design and yet it is important to be able to get software design and coding started without having to deal with the circuit board art work and fabrication of a board with fine pitch parts such as TQFP-100 type packages. I have found the microcontrollers from Silicon Labs to be very nice parts and can fit to project requirments well.
One such part I utilized in a recent design was the C8051F126. This ia a very high performance microcontroller with 128K bytes of FLASH memory and an onboard 8K byte XDATA memory space. The device is available with 8 ports (yes that is 64 bits of general purpose port I/O !!) in a TQFP-100 package. For this project it was necessary to get on with having a software development brassboard in a very short period of time. The technique I used to get to a working development platform in the shortest amount of time was to purchase a Silicon Labs Evaluation Board for this processor from DigiKey. A close up picture of this development board is shown below....
Notable features of this board are the fact that it has a place to connect power, an onboard RS232 connection to one of the UARTs on the 'F124/6 chip, eight 10-pin headers that provide direct connection to each of the 8 ports of the processor, and most importantly a 96-pin DIN connector that has connections to all of the processor signals.
This DIN connector is easy to connect to providing a means to attach circuitry to the development board in a robust manner. The mating 96-pin connector is a right angle through hole part on 0.1" by 0.1" (2.54 mm x 2.54 mm) pin centers in three rows of 32 pins. This makes it possible to wire additional circuitry using industrial standard "vector board" or to make an attachment circuit board. I show below a picture of a board I made to mate with the evaluation board with this technigue....
The attachment board was made by generating artwork with a PC Windows based artwork layout package. The resulting Gerber files were sent to a company called AP Circuits in Canada that can make two or four boards, such as that shown, within 2 days for a cost of about 150 US $. A close up of the add-on board, as shown here, will reveal the hand assembled boards that are 2 sided technology with plated through holes. AP Circuits prototype boards do not have any solder mask or silk screen (which keeps the cost down) thus making it easy to probe the traces and make etch-cut and hay-wire changes as the circuit concepts finalize durng the software development process.
