Dallas > DallasDS87C550
Modified: May 15, 2005, 9:10 pm
Model:DS87C550 QCL
Data Code:0340
Architecture:8 bit MCU
Used in:Control applications
Description: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