To get a 50-ms delay, what decimal value should be loaded into the 8051 timer re

Question

To get a 50-ms delay, what decimal value should be loaded into the 8051 timer register using 16-bit mode? Assume that XTAL = 12 MHz. 19456 15536 46080 65536 For all available timer modes in the 8051, which is the largest bit size for Timer 0 and Timer 1? 8 13 16 32 Which of the following is a true statement regarding 8051 timers? 8051 timers only count up. 8051 timers only count down. 8051 timers can count both up and down. All 8051 timers can be used to control baud rate. In timing applications, 8051 timers can be started or stopped by _____ the TF control bits the TR control bits an external gating signal either the TR control bits or an external gating signal

Explanation / Answer

1)
Given that the processor is clocked by a 12MHz crystal.That means, the timer clock input will be 12MHz/12 = 1MHz
Hence,the time taken for the timer to make one increment = 1/1MHz = 1uS

The maximim number of counts possible for a 16 bit timer is 2^16 = 65536
Let TH be the value value that has to be loaded to TH registed and TL be the value that has to be loaded to TL register.
Then, THTL = Hexadecimal equivalent of (65536-X) where (65536-X) is considered in decimal.

Here dalay X = 50MS=50000us

65536 – X = 65536 – 50000 = 15536

Answer: B i.e 15536.

2) 16 is the largest bit size for timer 0.

ANS: c

3) 8051 only counts up . This only the main advantage of 8051 timer.

ANS:A

4)Bit 6 and bit 4 are the timer run-control bits (TRx). A timer is started by setting TRx and stopped by clearing TRx.

ANS: B

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.