I'm assuming your planning to develop your own PCB to use with the MC9S12XDT512. The components needed to get this device up and running are rather simple. I suggest you take a look at
AN2727. This application note talks about hardware design considerations using the HCS12 D family. Now, keep in mind that the MC9S12XDT512 is part of the
HCS12X family. This family is an enhancement of the HCS12 adds a co-processor called the XGATE. The application note talks to the HCS12, but many of the same hardware implementations remain the same. As a matter of fact, the D-family in the HCS12X is pin to pin compatible with the D-family in the HCS12.
Now, to program the device the HCS12(X) use a BDM module. This module uses a single pin BDM interface to modify/read internal MCU memory. We recommend that customers route this BDM pin to a 6-pin (2x3) BDM port header. There are several 3rd party tool vendors that sell BDM programmers for the HCS12(X) and software tools that support it. This 6 pin connector is standard and includes (Vdd-pin6 ,Vss-pin2,BDM-pin1, Reset-pin4, and 2 no connect pins-pin3 and 5). In the olden days of the HC12 (no S), some of the no connect pins were used for Vpp, which is an external programming voltage. This is not necessary on the HCS12(X) families.
So for my BDM programmer I use the USB BDM Multilink from P&E that supports the HCS08/HCS12/HCS12X families. For my software tools, I use CodeWarrior for HC12 V4.5.
I hope this email helps you get going!
