Need Firmware for PID Control for Freescale mc9s08dz128clh Micro

I have a board with a Freescale mc9s08dz128clh micro with digital and analog input channels, and 1 analog output channel. Analog output goes through a DAC121C085 MSOP. I need some PID code to control via the analog output line with feedback on either the digital input channel or the analog input channel. The P, I, D coefficients, whether to use the analog or digital channel, and the setpoint for the digital or analog channel will be sent to the micro via USB commands. I have firmware for the Freescale which produces an analog output, and other firmware which displays voltage from an analog channel if you want some firmware examples.