We do not have a standard 16 bit stack.  The standard embedded BACstac/32 is a 32 bit stack. 

We do have a few options for you:

1) Our Eplus series is based on a 16 bit stack (x186).  If you are willing to purchase a custom solution we could port this to your target system. 

2) Our LC3020 BACnet chip would be a powerful alternative.  This is an ARM7 with many features together with full BACnet code in a complete development environment.  This is appropriate for medium price/power applications as the chip costs approx. $17 in 1000's.

3) If you are just starting your BACnet integration, please consider our EasyBAC module as this lets you create a BACnet product within weeks.  Please look at the description of this product.

4) There are some very inexpensive ARM7 chips on the market (some as low as $4).  If you wanted to go with this processor, our LC3020 code could be ported as a custom project.