AP1635

The AP1635 is designed as one kind of fuel injection control for a 12 cylinder formula 1 engine. It belongs to the C166 family that is perhaps unique in having 16 high speed I/O pins coupled to a capture and compare (CAPCOM) unit that can be used either as pulse generators or event detectors.

The combination of a very fast RISC-like CPU and a 16 channel capture and compare unit (CAPCOM) allows the easy generation of multiple pulse trains, all locked to a single timebase. Consequently, the AP1635 finds many applications in areas such as motor control and automotive engine management where the production of precisely timed pulse trains are required.

At each TDC, the capture register CC15 latches the value of a free running 16 bit timer, running at a 1.6ms per count. An interrupt service routine is subsequently called, during which the C166 must make an analog to digital conversion of the throttle position (and hence mass airflow), read the injector firing angle, relative to the TDC from a table and then create a turn-on time-out using a compare output to turn that cylinder's injector on. It must also immediately switch off the injector, in case it is still on from the previous cycle, as might happen under high acceleration conditions. If you want to know more information such as the electrical characteristics about the AP1635, please download the datasheet in www.seekic.com or www.chinaicmart.com .