DS87C520-QNL+

The DS87C520-QNL+ is an EPROM/ROM high speed microcontroller in 44 pin PLCC package. It is a fast 8051 compatible microcontroller. It features a redesigned processor core without wasted clock and memory cycles. As a result, the devices execute every 8051 instruction between 1.5 and 3 times faster than the original for the same crystal speed. The DS87C520 offer a maximum crystal speed of 33MHz resulting in apparent execution speeds of 82.5MHz (approximately 2.5X). It includes three timer/counters, serial port and four 8-bit I/O ports. It feature 16kB of EPROM or mask ROM with an extra 1kB of data RAM. It includes a second full hardware serial port, seven additional interrupts, programmable watchdog timer, brownout monitor and power-fail reset. The device also provides dual data pointers (DPTRs) to speed block data memory moves. It also can adjust the speed of MOVX data memory access from two to nine machine cycles for flexibility in selecting external memory and peripherals.