Core8051 is a soft IP version of the 8-Bit 8051 Microcontroller that is ASM51 Compatible. At one clock per instruction Core8051 runs much faster and has substantially increased throughput compared to the original 8051 implementations. The core can be used to run programs written for the 8051 without change, and is compatible with the existing 8051 tools. Core8051 supports 13 interrupts and has a UART, 2 counter/timers, and 4 8-bit ports. The SFR bus is fully supported and up to 101 external SFRs can be added