PRELIMINARY
8XC251SA/SB/SP/SQ
HIGH-PERFORMANCE
CHMOS MICROCONTROLLER
Commercial/Express
s
Real-time and Programmed Wait State
Bus Operation
s
Binary-code Compatible with MCS
®
51
s
Pin Compatible with 44-pin PLCC and 40-
pin PDIP MCS 51 Sockets
s
Register-based MCS
®
251 Architecture
— 40-byte Register File
— Registers Accessible as Bytes, Words,
or Double Words
s
Enriched MCS 51 Instruction Set
— 16-bit and 32-bit Arithmetic and Logic
Instructions
— Compare and Conditional Jump
Instructions
— Expanded Set of Move Instructions
s
Linear Addressing
s
256-Kbyte Expanded External Code/Data
Memory Space
s
ROM/OTPROM/EPROM Options:
16 Kbytes (SB/SQ), 8 Kbytes (SA/SP), or
without ROM/OTPROM/EPROM
s
16-bit Internal Code Fetch
s
64-Kbyte Extended Stack Space
s
On-chip Data RAM Options:
1-Kbyte (SA/SB) or 512-Byte (SP/SQ)
s
8-bit, 2-clock External Code Fetch in
Page Mode
s
Fast MCS 251 Instruction Pipeline
s
User-selectable Configurations:
— External Wait States (0-3 wait states)
— Address Range & Memory Mapping
— Page Mode
s
32 Programmable I/O Lines
s
Seven Maskable Interrupt Sources
with Four Programmable Priority
Levels
s
Three Flexible 16-bit Timer/counters
s
Hardware Watchdog Timer
s
Programmable Counter Array
— High-speed Output
— Compare/Capture Operation
— Pulse Width Modulator
— Watchdog Timer
s
Programmable Serial I/O Port
— Framing Error Detection
— Automatic Address Recognition
s
High-performance CHMOS Technology
s
Static Standby to 16-MHz Operation
s
Complete System Development
Support
— Compatible with Existing Tools
— New MCS 251 Tools Available:
Compiler, Assembler, Debugger, ICE
s
Package Options (PDIP, PLCC, and
Ceramic DIP)
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.
COPYRIGHT © INTEL CORPORATION, 1996
May 1996
Order Number:
272783-003
Information in this document is provided in connection with Intel products. No license, express or implied, by
estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in
Intel’s Terms and Conditions of Sale for such products, Intel assumes no liability whatsoever, and Intel
disclaims any express or implied warranty, relating to sale and/or use of Intel products including liability or
warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright
or other intellectual property right. Intel products are not intended for use in medical, life saving, or life
sustaining applications.
Intel retains the right to make changes to specifications and product descriptions at any time, without notice.
*Third-party brands and names are the property of their respective owners.
Copies of documents which have an ordering number and are referenced in this document, or other Intel
literature, may be obtained from:
Intel Corporation
P.O. Box 7641
Mt. Prospect IL 60056-764
or call 1-800-548-4725
8XC251SA/SB/SP/SQ HIGH-PERFORMANCE CHMOS MICROCONTROLLER
System Bus and I/O Ports
P0.7:0
P2.7:0
Code
OTPROM/ROM
8 Kbytes
or
16 Kbytes
I/O Ports and
Peripheral Signals
P1.7:0
P3.7:0
Port 0
Drivers
Port 2
Drivers
Data RAM
512 Bytes
or
1024 Bytes
Port 1
Drivers
Port 3
Drivers
Memory Data (16)
Memory Address (16)
Watchdog
Timer
Bus Interface
Code Bus (16)
Code Address (24)
Peripheral
Interface
Timer/
Counters
Instruction Sequencer
Data Address (24)
Interrupt
Handler
IB Bus (8)
PCA
SRC2 (8)
Data Bus (8)
SRC1 (8)
Serial I/O
Clock
&
Reset
Peripherals
ALU
Register
File
Data
Memory
Interface
DST (16)
MCS
®
251 Microcontroller Core
Clock & Reset
8XC251SA/SB/SP/SQ Microcontroller
A4214-01
Figure 1. 8XC251SA/SB/SP/SQ Block Diagram
PRELIMINARY
3
8XC251SA/SB/SP/SQ HIGH-PERFORMANCE CHMOS MICROCONTROLLER
1.0
NOMENCLATURE
X
Te
XX
ck
Pa
8
X
o
Pr
X
o
Pr
XXXXX
o
Pr
XX
De
Figure 2. The 8XC251SA/SB/SP/SQ Family Nomenclature
Table 1. Description of Product Nomenclature
Parameter
Temperature and Burn-in
Options
Options
no mark
T
Packaging Options
N
P
C
Program Memory Options
0
3
7
Process Information
Product Family
Device Memory Options
C
251
SA
SB
SP
SQ
Device Speed
16
Description
Commercial operating temperature range (0°C to 70°C) with
Intel standard burn-in.
Express operating temperature range (-40°C to 85°C) with
Intel standard burn-in.
44-pin Plastic Leaded Chip Carrier (PLCC)
40-pin Plastic Dual In-line Package (PDIP)
40-pin Ceramic Dual In-line Package (Ceramic DIP)
Without ROM/OTPROM/EPROM
ROM
User programmable OTPROM/EPROM
CHMOS
8-bit control architecture
1-Kbyte RAM/8-Kbyte ROM/OTPROM/EPROM
1-Kbyte RAM/16-Kbyte ROM/OTPROM/EPROM or without
ROM/OTPROM/EPROM
512-byte RAM/8-Kbyte ROM/OTPROM/EPROM
512-byte RAM/16-Kbyte ROM/OTPROM/EPROM or without
ROM/OTPROM/EPROM
External clock frequency
mp
vic
gr
ce
du
ing
ag
am
pe
eS
atu
er
ss
Inf
ct
m
Fa
-m
a
re
tio
ns
Op
tio
-in
Op
rn
Bu
ns
em
or
ma
ed
ily
or
nd
yO
n
tio
s
on
pti
A2815-01
4
PRELIMINARY
8XC251SA/SB/SP/SQ HIGH-PERFORMANCE CHMOS MICROCONTROLLER
Table 2 lists the proliferation options. See Figure 2 for the 8XC251SA/SB/SP/SQ family nomenclature.
.
Table 2. Proliferation Options
8XC251SA/SB/SP/SQ
(0 – 16 MHz; 5 V ±10%)
80C251SB16
80C251SQ16
83C251SA16
83C251SB16
83C251SP16
83C251SQ16
87C251SA16
87C251SB16
87C251SP16
87C251SQ16
Table 3 lists the 8XC251SA/SB/SP/SQ packages.
Table 3. Package Information
Pkg.
N
P
C
TN
TP
Definition
44 ld. PLCC
40 ld. Plastic DIP
40 ld. Ceramic DIP
44 ld. PLCC
40 ld. Plastic DIP
Temperature
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
CPU-only
CPU-only
ROM
ROM
ROM
ROM
OTPROM/EPROM
OTPROM/EPROM
OTPROM/EPROM
OTPROM/EPROM
PRELIMINARY
5
