ChibiOS Free Embedded RTOS

I would like to create a 16 bit DAC in STM32F103RET6. ButSTM32F103RET6 only has 12 bit DAC. How do I implement a higher resolution DAC in STM32F103RET6?
Thank you. Please see link below
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjBhcq295DMAhWGkCwKHZP4AHQQFggkMAE&url=http%3A%2F%2Fwww.cypress.com%2Ffile%2F136326%2Fdownload&usg=AFQjCNGMTYfBJtqGyTpFVwAPRUurSabTYg&sig2=50MhyHEtaBsOAstU7zvBBQ&bvm=bv.119408272,d.bGg

hi,

I don't know about that paper but you could make a 16 bits DAC using a PWM with all 16 bits of resolution, then pass the signal through a low pass filter.

Giovanni