DS87C550 Datasheet, PDF (2/50 Pages) Dallas Semiconductor – EPROM High-Speed Micro with A/D and PWM

DS87C550
DESCRIPTION
The DS87C550 EPROM High-Speed Micro with A/D 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
33 MHz, resulting in apparent execution speeds of up to 99 MHz.
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 8 kbytes of EPROM with an
extra 1 kbyte 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 12 MHz, standard operation has a machine cycle rate of 3 MHz. In Power Management
Mode, software can select an 11.7 kHz (12 MHz/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.
ORDERING INFORMATION
PART NUMBER
PACKAGE
DS87C550-QCL
68-pin PLCC
DS87C550-FCL
80-pin PQFP
DS87C550-QNL
68-pin PLCC
DS87C550-FNL
80-pin PQFP
DS87C550-KCL
68-pin windowed CLCC
MAX. CLOCK SPEED
33 MHz
33 MHz
33 MHz
33 MHz
33 MHz
TEMPERATURE RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to 70°C
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