Targets: Test & Measurement
The P-51 is an 8051/52 core with additional features such as an ISA interface and extra RAM. Unlike typical 8051s, it is not designed to be a standalone device — it requires a host, and would be used in embedded applications as a peripheral. The P-51 includes all of the regular 8051 ports on one side of the 100-pin package and an ISA bus interface on the other side, making it suitable for embedded industrial applications based on PC ISA boards or PC-104 modules.
One advantage of using this device on an ISA/PC-104 board is that Windows applications can not deal with peripheral hardware and interrupts in real time, but this device can. Thus, applications can be programmed into the P-51's on-chip memory to perform the service routines for real-world interrupts and events. The P-51 is in-circuit programmable at reset, so the 8051 code can be downloaded and upgraded. The P-51 has built-in debugging features (Breakpoints and Single Step) to allow in-circuit code development without an ICE (In-Circuit-Emulator).
Functionally, the P-51 retains all the standard 8051/52 instructions and registers, adding a Square Root function not found in an 8051. Its unique internal dual-port RAM can be accessed from the 8051 code on one side and from the application software on the other side.