The Dallas Semiconductor High-Speed Microcontroller is an 8051-compatible device that provides improved performance and power consumption compared to the original version. It retains instruction set and object code compatibility with the 8051, yet performs the same operations in fewer clock cycles. Consequently, more throughput is possible for the same crystal speed. As an alternative, the High-Speed Microcontroller can be run slowly to save power. The more efficient design allows a much slower crystal speed to get the same results as an original 8051, using much less power. The fundamental innovation of the High-Speed Microcontroller is the use of only four clocks per instruction cycle compared with twelve for the original 8051. This results in up to 3 times improvement in performance. In addition, the High-Speed Microcontroller is updated with several new peripherals and features while providing all of the standard features of an 80C32. These include 256 bytes of on-chip RAM, 32 I/O ports, three 16-bit timer/counters, and an on-chip UART. All devices provide 256 bytes of RAM for variables and stack. 128 bytes can be reached using direct addressing and 128 using indirect addressing.