PRELIMINARY
COPY RIGH T © INTEL CORPORATION, 19 96 May 1996 Order Number: 272783-003
8XC251SA/SB/SP/SQ
HIGH-PERFORMANCE
CHMOS MICROCONTROLLER
Comm ercial/Express
A member of the Intel family of 8-bit MCS 251 microcontrollers, the 8XC251SA/SB/SP/SQ is binary-code
compatible with MCS 51 microcontrollers and pin compatible with 40-pin PDIP and 44-pin PLCC MCS 51
microcontrollers. MCS 251 microcontrollers feature an enriched instruction set, linear addressing, and
efficient C-language support. The 8XC251SA/SB/SP/SQ has 512 bytes or 1 Kbyte of on-chip RAM and is
available with 8 Kbytes or 16 Kbytes of on-chip ROM/OTPROM/EPROM, or without ROM/OTPROM/EPROM.
A variety of features can be selected by new user-programmable configurations.
■ Real-time and Programmed Wait St ate
Bus Operation
■ Binary-code Compatible with MC S
®
51
■ Pin Compatible with 44-pin PLCC and 40-
pin PDIP MCS 51 Sockets
■ Register-based MCS
®
251 A rchitecture
— 40-byte Register File
— Registers Accessible as Bytes, W ords,
or Double Words
■ Enriched MCS 51 Instruction Set
— 16-bit and 32-bit Ari thmetic and Logic
Instructions
— Compare and Conditio nal Jump
Instructio ns
— Expanded Set of Move Instructions
■ Linear Addressing
■ 256-Kbyte Expanded External Code/Data
Memory Space
■ ROM/OTPROM/EPROM Options:
16 Kbytes (SB/SQ), 8 Kbytes (SA/SP), or
without ROM/OTPROM/EPROM
■ 16-bit Internal Code Fetch
■ 64-Kbyte Ext ended St ack Space
■ On-chip Data RAM Options:
1-Kbyte (SA/SB) or 512-Byte (SP/SQ)
■ 8-bit, 2-clock External Code Fetch in
Page Mode
■ Fast MCS 251 Instruction Pipeline
■ User-selectable Configurations:
— External W ait States (0-3 wait states)
— Address Range & Memory Mapping
— Page Mode
■ 32 Programmable I/O Lines
■ Seven Maskable Interrupt Sources
with Four Programmable Priority
Levels
■ Three Flexible 16-bit Timer/counters
■ Hardware Watch dog Timer
■ Programmable Counter Arr ay
— High-speed Output
— Compare/Capture Operation
— Pulse Width Modulator
— Watc h dog Timer
■ Programmable Serial I/O Por t
— Framing Error Detection
— Automatic Address Recognition
■ High-performance CHMOS Technology
■ Static Standby to 16-MHz Operation
■ Complete System Development
Support
— Compatible with Existing Tools
— New MCS 251 Tools Avail able:
Compiler, Assembler, Debugger, ICE
■ Package Options (PDIP, PLCC, and
Ceramic DIP)