The DS80C390 is a fast 8051-compatible microprocessor. The redesigned processor core executes 8051 instructions up to 3 times faster than the original for the same crystal speed. The DS80C390 supports a maximum crystal speed of 40 MHz, resulting in apparent execution speeds of 100 MHz (approximately 2.5X). An optional internal frequency multiplier allows the microprocessor to operate at full speed with a reduced crystal frequency, reducing EMI. A hardware math accelerator further increases the speed of 32 and 16 bit multiply and divide operations, as well as high-speed shift, normalization and accumulate functions.……