DS87C550 EPROM High-Speed Microcontroller with ADC and PWM
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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 pin-out 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 two and 12 machine cycles for
flexibility in selecting memory and peripherals.
Power Management Mode (PMM) is useful for portable or battery-powered applications. This feature
allows software to select a lower speed clock as the main time base. While normal operation has a
machine cycle rate of 4 clocks per cycle, the PMM allows the processor to run at 1024 clocks per cycle.
For example, at 12MHz, standard operation has a machine cycle rate of 3MHz. In Power Management
Mode, software can select an 11.7 kHz (12MHz/1024) machine cycle rate. There is a corresponding
reduction in power consumption due to the processor running slower.
The DS87C550 also offers two features that can significantly reduce electromagnetic interference (EMI).
One EMI reduction feature allows software to select a reduced emission mode that disables the ALE
signal when it is unneeded. The other EMI reduction feature controls the current to the address and data
pins interfacing to external devices producing a controlled transition of these signals.
Designers using the DS87C550 as an upgrade for the 87C552 or similar 8051-based microcontrollers
with A/D capability should read Application Note 2: The DS87C550 as an Upgrade for 8051 Derivatives.
ORDERING INFORMATION
PART
MAX CLOCK
SPEED (MHz)
TEMP RANGE
PIN-PACKAGE
DS87C550-QCL
33
0°C to +70°C
68 PLCC
DS87C550-QCL+
33
0°C to +70°C
68 PLCC
DS87C550-FCL
33
0°C to +70°C
80 PQFP
DS87C550-FCL+
33
0°C to +70°C
80 PQFP
DS87C550-QNL
33
-40°C to +85°C
68 PLCC
DS87C550-QNL+
33
-40°C to +85°C
68 PLCC
DS87C550-FNL
33
-40°C to +85°C
80 PQFP
DS87C550-FNL+
33
-40°C to +85°C
80 PQFP
DS87C550-KCL*
33
0°C to +70°C
68 Windowed CLCC
+ Denotes a Pb-free/RoHS-compliant device.
*
The windowed ceramic LCC package is intrinsically Pb free.