Dallas > DallasDS87C520
Modified: May 15, 2005, 9:03 pm
Model:DS87C520 MCL
Data Code:0239
Architecture:8 bit MCU
Used in:Control applications
Description:The DS87C520/DS83C520 EPROM/ROM high-speed
microcontrollers are fast 8051-compatible
microcontrollers. They feature 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.
Typical applications will see a speed improvement
of 2.5 times using the same code and the same
crystal. The DS87C520/DS83C520 offer a maximum
crystal speed of 33MHz, resulting in apparent
execution speeds of 82.5MHz (approximately 2.5X).

The DS87C520/DS83C520 are pin compatible with all
three packages of the standard 8051, and include
standard resources such as three timer/counters,
serial port, and four 8-bit I/O ports. They
feature 16kB of EPROM or mask ROM with an extra
1kB of data RAM. Both OTP and windowed packages
are available.

Besides greater speed, the microcontroller
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