Counter Device in Microcontrollers

All the bits that are of Timer 1 will now be tied to ______.

TH0

When Timer 0 is in split mode, the real Timer 1 can be set in modes 0, 1 or 2, but it cannot be started/stopped as the bits that do that are now linked to ______.

TH0

TL0 sets TF0 and TH0 sets ______.

TF1

When the TF1 is used by TH0 timer, the Timer1 is used as ______ Rate Generator.

Baud Signup and view all the answers

In Mode 3 of Timer0, the 8051 has three timers. One 8-bit timer by TH0, another 8-bit timer/counter by TL0, and one 16-bit timer/counter by ______.

Timer1 Signup and view all the answers

To calculate the values to be loaded into TL and TH register, we can use the crystal frequency of 11.0592 MHz. Divide the desired time delay by 1.085 us, Perform 65536 - n. Where n is the decimal value be caught in step 1, Convert the result of step to 2 to hex. Where YYXX is the initial hex values to be loaded into the timer register, Set TL equal to xx and TH equal to ______.

YY Signup and view all the answers

The 16-bit register of Timer 0/1 is accessed as ______ and high-byte.

low Signup and view all the answers

The low-byte register of Timer 0/1 is called ______ (Timer 0/1 low byte).

TL0 Signup and view all the answers

The high-byte register of Timer 0/1 is called ______ (Timer 0/1 high byte).

TH0 Signup and view all the answers

The instruction MOV ______/TL1, #4H moves the value into the low-byte of Timer #0/1.

TL0 Signup and view all the answers

Every Timer needs a clock to work, and 8051 provides it from an external ______ which is the main clock source for Timer.

crystal Signup and view all the answers

The ______ register in 8051 is used for setting the mode of Timer 0 and Timer 1.

TMOD Signup and view all the answers

The internal circuitry in the 8051 microcontrollers provides a clock source to the timer which is 1/12th of the frequency of crystal attached to the microcontroller, also called Machine cycle frequency. For example, suppose we have a crystal frequency of 11.0592 MHz then the microcontroller will provide 1/12th i.e. ______ clock frequency= (crystal Osc.frequency)/12 = (11.0592 MHz)/12 = 921.6 KHz. Period T= 1/ (921.6 kHz) =1.085 μS. TIMERS OF 8051- TIMER MODES MODE-0 (13-BIT TIMER MODE). Mode 0 is a 13-bit timer mode for which 8-bit of THx and 5-bit of TLx (as Prescaler) is used. It is mostly used for interfacing possible with old MCS-48 family microcontrollers. 8-bit of THx and lower 5-bit of TLx used to form a total 13-bit timer. Higher 3-bits of TLx should be written as zero while using timer mode0, or it will affect the result. In this mode the timer is used as 13-bit up counter. The 13bit value is between 0000H-1FFFH. The value is loaded into TL (5 bits) and TH(8 bits). When the timer reaches its maximum of 1FFFH it rolls over to 0000H and TF is raised. Here TLx will count from 0 to 31. When it in incremented from 31 it will reset to zero and increment THx. This effectively only 13 bit of timer is being used. The timer interrupt flag TFx is set when the timer rolls over from 1FFFH-0000H.

Timer Signup and view all the answers

Mode 0 is a 13-bit timer mode for which 8-bit of and 5-bit of TLx (as Prescaler) is used. It is mostly used for interfacing possible with old MCS-48 family microcontrollers. 8-bit of and lower 5-bit of TLx used to form a total 13-bit timer. Higher 3-bits of TLx should be written as zero while using timer mode0, or it will affect the result. In this mode the timer is used as 13-bit up counter. The 13bit value is between 0000H-1FFFH. The value is loaded into TL (5 bits) and TH(8 bits). When the timer reaches its maximum of 1FFFH it rolls over to 0000H and TF is raised. Here TLx will count from 0 to 31. When it in incremented from 31 it will reset to zero and increment __. This effectively only 13 bit of timer is being used. The timer interrupt flag TFx is set when the timer rolls over from 1FFFH-0000H.

THx Signup and view all the answers

Mode 0 is a 13-bit timer mode for which 8-bit of THx and 5-bit of (as Prescaler) is used. It is mostly used for interfacing possible with old MCS-48 family microcontrollers. 8-bit of THx and lower 5-bit of used to form a total 13-bit timer. Higher 3-bits of should be written as zero while using timer mode0, or it will affect the result. In this mode the timer is used as 13-bit up counter. The 13bit value is between 0000H-1FFFH. The value is loaded into TL (5 bits) and TH(8 bits). When the timer reaches its maximum of 1FFFH it rolls over to 0000H and TF is raised. Here will count from 0 to 31. When it in incremented from 31 it will reset to zero and increment THx. This effectively only 13 bit of timer is being used. The timer interrupt flag TFx is set when the timer rolls over from 1FFFH-0000H.

TLx Signup and view all the answers

In this mode the timer is used as 13-bit counter. The 13bit value is between 0000H-1FFFH. The value is loaded into TL (5 bits) and TH(8 bits). When the timer reaches its maximum of 1FFFH it rolls over to 0000H and TF is raised. Here TLx will count from 0 to 31. When it in incremented from 31 it will reset to zero and increment THx. This effectively only 13 bit of timer is being used. The timer interrt flag TFx is set when the timer rolls over from 1FFFH-0000H.

up Signup and view all the answers

The value is ______ into TL (5 bits) and TH(8 bits). When the timer reaches its maximum of 1FFFH it rolls over to 0000H and TF is raised. Here TLx will count from 0 to 31. When it in incremented from 31 it will reset to zero and increment THx. This effectively only 13 bit of timer is being used. The timer interrupt flag TFx is set when the timer rolls over from 1FFFH-0000H.

loaded Signup and view all the answers

The timer interrupt flag ______ is set when the timer rolls over from 1FFFH-0000H.

TFx Signup and view all the answers