The PIC17CR42, PIC17C42A, PIC17C43, PIC17CR43, and PIC17C44 devices include architectural enhancements over the PIC17C42. These enhancements will be discussed throughout this datasheet.

The PIC17C4X devices are 40/44-Pin, EPROM/ROM-based members of the versatile
PIC17CXX family of low-cost, high-performance, CMOS, fully-static, 8-bit microcontrollers.
All PIC16/17 microcontrollers employ an advanced RISC architecture. The PIC17CXX has enhanced core features, 16-level deep stack, and multiple internal and external interrupt sources. The separate instruction and data buses of the Harvard architecture allow a 16-bit
wide instruction word with a separate 8-bit wide data.

The two stage instruction pipeline allows all instructions to execute in a single cycle, except for program branches (which require two cycles). A total of 55 instructions (reduced instruction set) are available in the PIC17C42 and 58 instructions in all the other devices. Additionally, a large register set gives some of
the architectural innovations used to achieve a very high performance. For mathematical intensive applications all devices, except the PIC17C42, have a single cycle 8 x 8 Hardware Multiplier.