Hi
What crystal will you use with the device? If the crystal is 16MHz or slower, you can use the JB8. The BDM communication speed is determined by the crystal speed and not the bus speed. You can therefore operate your device at 50MHz bus (100MHz XGATE) using the PLL and still talk to it using JB8 TBDML.
There are only two S12 devices in the whole Freescale potrfolio which do not enable the use of TBDML with JB8:
1. NE64 - requires 25MHz crystal, JB16 helps here
2. XF?128 - requires 40MHz crystal, even JB16 is too slow for this one.
All the other devices are typically used with 4 or 8MHz crystals and TBDML works with them perfectly even at their highest possible speed.
I have not developed a JB16 version myself. There are some kicking around, but I will let authors of the SW/HW to comment.
Daniel
Message Edited by DanielM on 2006-09-19 09:20 AM