Описание
The DS87C520 EPROM 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 offer a maximum crystal speed of 33MHz, resulting in apparent execution speeds of 82.5MHz (approximately 2.5X). The DS87C520 is 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 peripherals. A new Power Management Mode (PMM) is useful for portable 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 runs the processor at 64 or 1024 clocks per cycle. For example, at 12MHz, standard operation has a machine cycle rate of 3MHz. In Power Management Mode, software can select either 187.5kHz or 11.7kHz machine cycle rate. There is a corresponding reduction in power consumption when the processor runs slower. The EMI reduction feature allows software to select a reduced emission mode. This disables the ALE signal when it is unneeded.
- 80C52 Compatible 8051 Pin- and Instruction-Set Compatible Four 8-Bit I/O Ports Three 16-Bit Timer/Counters 256 Bytes Scratchpad RAM
- Large On-Chip Memory 16kB Program Memory 1kB Extra On-Chip SRAM for MOVX
- ROMSIZE Feature Selects Internal ROM Size from 0 to 16kB Allows Access to Entire External Memory Map Dynamically Adjustable by Software Useful as Boot Block for External Flash
- High-Speed Architecture 4 Clocks/Machine Cycle (8051 = 12) Runs DC to 33MHz Clock Rates Single-Cycle Instruction in 121ns Dual Data Pointer Optional Variable Length MOVX to Access Fast/Slow RAM/Peripherals
- Power Management Mode Programmable Clock Source to Save Power CPU Runs from (crystal/64) or (crystal/1024) Provides Automatic Hardware and Software Exit
- EMI Reduction Mode Disables ALE
- Two Full-Duplex Hardware Serial Ports
- High Integration Controller Includes: Power-Fail Reset Early-Warning Power-Fail Interrupt Programmable Watchdog Timer
- 13 Interrupt Sources with Six External
- Available in 40-pin PDIP, 44-Pin PLCC, 44-Pin TQFP, and 40-Pin Windowed CERDIP
- Factory Mask DS83C520 or EPROM (OTP) DS87C520
