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Intel 8XC251SA, 8XC251SP, 8XC251SQ, 8XC251SB, Embedded Microcontroller manual TR0 GATE0, TR1

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

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8XC251SA, SB, SP, SQ USER’S MANUAL

Timer 1 is controlled by the four high-order bits of the TMOD register (Figure 8-5) and bits 7, 6, 3, and 2 of the TCON register (Figure 8-6). The TMOD register selects the method of timer gating (GATE1), timer or counter operation (T/C1#), and mode of operation (M11 and M01). The TCON register provides timer 1 control functions: overflow flag (TF1), run control (TR1), inter- rupt flag (IE1), and interrupt type control (IT1).

Timer 1 operation in modes 0, 1, and 2 is identical to timer 0. Timer 1 can serve as the baud rate generator for the serial port. Mode 2 is best suited for this purpose.

For normal timer operation (GATE1 = 0), setting TR1 allows timer register TL1 to be increment- ed by the selected input. Setting GATE1 and TR1 allows external pin INT1# to control timer op- eration. This setup can be used to make pulse width measurements. See section 8.5.2, “Pulse Width Measurements.”

Timer 1 overflow (count rolls over from all 1s to all 0s) sets the TF1 flag generating an interrupt request.

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XTAL1

12

1/12 FOSC

 

 

 

0

 

 

Interrupt

 

TL0

Overflow

Request

 

 

TF0

T0

1

(8 Bits)

 

 

 

 

C/T0#

 

 

 

TR0

 

 

 

 

GATE0

 

 

 

 

 

 

 

Overflow

Interrupt

 

 

TH0

Request

INT0#

 

1/12 FOSC

 

TF1

 

 

(8 Bits)

 

 

 

 

TR1

 

 

 

 

 

 

A4112-02

Figure 8-4. Timer 0 in Mode 3, Two 8-bit Timers

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Intel 8XC251SA, 8XC251SP, 8XC251SQ, 8XC251SB, Embedded Microcontroller manual TR0 GATE0, TR1
Page 139 Page 141

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.