Manuals / Intel / Computer Equipment / Computer Hardware

Intel 8XC251SP, 8XC251SA, 8XC251SQ, 8XC251SB, Embedded Microcontroller manual CEX20

Models: Embedded Microcontroller 8XC251SP 8XC251SA 8XC251SQ 8XC251SB

1 458
Download 458 pages 25.38 Kb
Page 396
Image 396

8XC251SA, SB, SP, SQ USER’S MANUAL

Table B-2. Signal Descriptions (Continued)

Signal

Type

Description

Alternate

Name

Function

 

 

 

 

 

 

CEX2:0

I/O

Programmable Counter Array (PCA) Input/Output Pins. These

P1.5:3

CEX3

 

are input signals for the PCA capture mode and output signals for

P1.6/WAIT#

CEX4

 

the PCA compare mode and PCA PWM mode.

P1.7/A17/WCLK

 

 

 

 

EA#

I

External Access. Directs program memory accesses to on-chip or

VPP

 

 

off-chip code memory. For EA# = 0, all program memory accesses

 

 

 

are off-chip. For EA# = 1, an access is to on-chip program memory

 

 

 

if the address is within the range of the on-chip program memory;

 

 

 

otherwise the access is off-chip. The value of EA# is latched at

 

 

 

reset. For devices without on-chip program memory, EA# must be

 

 

 

strapped to ground.

 

 

 

 

 

ECI

I

PCA External Clock Input. External clock input to the 16-bit PCA

P1.2

 

 

timer.

 

 

 

 

 

INT1:0#

I

External Interrupts 0 and 1. These inputs set bits IE1:0 in the

P3.3:2

 

 

TCON register. If bits IT1:0 in the TCON register are set, bits IE1:0

 

 

 

are set by a falling edge on INT1#/INT0#. If bits INT1:0 are clear,

 

 

 

bits IE1:0 are set by a low level on INT1:0#.

 

 

 

 

 

P0.7:0

I/O

Port 0. This is an 8-bit, open-drain, bidirectional I/O port.

AD7:0

 

 

 

 

P1.0

I/O

Port 1. This is an 8-bit, bidirectional I/O port with internal pullups.

T2

P1.1

 

 

T2EX

P1.2

 

 

ECI

P1.5:3

 

 

CEX2:0

P1.6

 

 

CEX3/WAIT#

P1.7

 

 

CEX4/A17/WCLK

 

 

 

 

P2.7:0

I/O

Port 2. This is an 8-bit, bidirectional I/O port with internal pullups.

A15:8

 

 

 

 

P3.0

I/O

Port 3. This is an 8-bit, bidirectional I/O port with internal pullups.

RXD

P3.1

 

 

TXD

P3.3:2

 

 

INT1:0#

P3.5:4

 

 

T1:0

P3.6

 

 

WR#

P3.7

 

 

RD#/A16

 

 

 

 

PROG#

I

Programming Pulse. The programming pulse is applied to this pin

ALE

 

 

for programming the on-chip nonvolatile memory.

 

 

 

 

 

PSEN#

O

Program Store Enable. Read signal output to external memory.

—

 

 

Asserted for the address range specified by configuration byte

 

 

 

UCONFIG0, bits RD1:0 (Table B-3). Also see RD#.

 

 

 

 

 

RD#

O

Read. Read signal output to external data memory. Asserted for

P3.7/A16

 

 

the address range specified by configuration byte UCONFIG0, bits

 

 

 

RD1:0 (Table B-3). Also see PSEN# and A16.

 

 

 

 

 

†The descriptions of A15:8/P2.7:0 and AD7:0/P0.7:0 are for the nonpage mode chip configuration (com- patible with 44-pin PLCC and 40-pin DIP MCS®51 microcontrollers). If the chip is configured for page mode operation, port 0 carries the lower address bits (A7:0), and port 2 carries the upper address bits (A15:8) and the data (D7:0).

B-4

Page 395 Page 397
Page 396
Image 396
Intel 8XC251SP, 8XC251SA, 8XC251SQ, 8XC251SB, Embedded Microcontroller manual CEX20
Page 395 Page 397

Embedded Microcontroller, 8XC251SP, 8XC251SA, 8XC251SQ, 8XC251SB specifications

The Intel 8XC251 series of embedded microcontrollers is a family of versatile and powerful devices, designed to meet the demands of a wide range of applications. With models such as the 8XC251SB, 8XC251SQ, 8XC251SA, and 8XC251SP, this series offers unique features while maintaining a high level of performance and reliability.

At the heart of the 8XC251 microcontrollers is the 8051 architecture, which provides a 16-bit processor capable of executing complex instructions efficiently. This architecture not only allows for a rich instruction set but also facilitates programming in assembly language and higher-level languages like C, which are essential for developing sophisticated embedded systems.

One of the significant features of the 8XC251 family is its integrated peripherals, including timer/counters, serial communication interfaces, and interrupt systems. These peripherals enable developers to implement timing functions, data communication, and real-time processing, all of which are crucial in modern embedded applications. The 8XC251SB and 8XC251SQ models, for instance, come equipped with multiple I/O ports that allow for interfacing with other devices and systems, enhancing their functionality in various environments.

The memory architecture of the 8XC251 devices is noteworthy, featuring on-chip ROM, RAM, and EEPROM. The on-chip memory allows for fast access times, which is essential for executing programs efficiently. Moreover, the EEPROM serves as non-volatile memory, enabling the storage of configuration settings and important data that must be retained even when power is lost.

In terms of operating voltage, the 8XC251 devices are designed to operate in a wide range, typically between 4.0V and 6.0V. This flexibility makes them suitable for battery-powered applications, where energy efficiency is critical. The power management features, including reduced power modes, further enhance their suitability for portable devices.

Lastly, the 8XC251 series is supported by a wide range of development tools and resources, allowing engineers and developers to streamline the development process. This support, combined with the microcontrollers' robust features, makes the Intel 8XC251 family a reliable choice for various embedded applications, such as industrial automation, automotive systems, and consumer electronics.

Overall, the Intel 8XC251SB, 8XC251SQ, 8XC251SA, and 8XC251SP deliver high performance, versatility, and ease of use, making them a preferred choice for embedded system designers looking to develop efficient and effective solutions.