The AN2131 does not implement the 8051's I/O using the SFRs. The AN2131 accesses the Port I/O via direct memory addresses. The Frameworks (under the Utils directory) handles the structure of the SFRs. The dev_io example is appropriate as an example. (Located on the web at www.cypress.com, under the dev kit). For the utilization of the timers, an example project can be found under the USB to serial examples. Refer to the USB to Serial reference design available here. This example contains an unsupported example of USB to serial on using the AN2131, which will show setting the timers up.