The DS87C550 EPROM high-speed microcontroller with ADC and PWM is a member of the fastest 100% 8051-compatible microcontroller family available. It features a redesigned processor core that removes wasted clock and memory cycles. As a result, it executes 8051 instructions up to three times faster than the original architecture for the same crystal speed. The DS87C550 also offers a maximum crystal speed of 33MHz, resulting in apparent execution speeds of up to 99MHz.
The DS87C550 uses an industry-standard 8051 pinout and includes standard resources such as three timer/counters and 256 bytes of scratchpad RAM. This device also features 8kB of EPROM with an extra 1kB of data RAM (in addition to the 256 bytes of scratchpad RAM), and 55 I/O ports pins. Both one-time programmable (OTP) and windowed packages are available.
Besides greater speed, the DS87C550 includes a second full hardware serial port, seven additional interrupts, a programmable watchdog timer, brownout monitor, and power-fail reset.
The DS87C550 also provides dual data pointers (DPTRs) to speed block data memory moves. The user can also dynamically adjust the speed of external accesses between 2 and 12 machine cycles for flexibility in selecting memory and peripherals.