What is the maximum delay that can generated by 16-bit timer 1 with a prescale value of 64 and a system clock frequency of 16 Mhz?
At this frequency, and using a 16-bit timer (MAX = 65535), the maximum delay is 4.096 ms.
What are timers in AVR?
Timers as registers In AVR, timers are of two types: 8-bit and 16-bit timers. In an 8-bit timer, the register used is 8-bit wide whereas in 16-bit timer, the register width is of 16 bits. This means that the 8-bit timer is capable of counting 2^8=256 steps from 0 to 255 as demonstrated below.
What is timer in AVR microcontroller?
A Timer is actually a counter that is increased every time when an instruction is executed. There are one to six timers in AVR Microcontrollers depending upon their family architecture. The AVR timers are of 8 bits and 16 bits.
How are AVR delays calculated?
To calculate a delay, you need to calculate the cycle time and then count how may cycles you need to reach the wanted delay. In your case, 1MHz clock means 1000000 cycles per second. So 1 cycle equals 1/1000000 seconds or 1us .
What are the methods of creating time delay in AVR?
There are three ways of doing this….The AVR design –
- Use Harvard architecture to get the maximum amount of code and data into the CPU.
- Use RISC architecture features such as fixed-size instructions.
- Use pipelining to overlap fetching and execution of instructions.
What is prescaler value?
The prescaler values, referred to as prescales, that may be configured might be limited to a few fixed values (powers of 2), or they may be any integer value from 1 to 2^P, where P is the number of prescaler bits. The purpose of the prescaler is to allow the timer to be clocked at the rate a user desires.
What is the difference between prescaler and Postscaler?
A prescaler is an electronic circuit used to reduce a high frequency electrical signal to a low frequency by integer division. Postscaler: A circuit that slows the rate of the interrupt generation(or WDT reset)from a counter/timer by dividing it down.
How do I add a delay in AVR assembly?
You can use timer/counter0 with prescalar=1024 and 1MHz clock for creating 250ms delay. Each 250 milliseconds one interrupt will be generated. 4 interrupts mean 1 second!
How do you do a time delay on AVR C?
In order to use the _delay_ms() function and get it to delay for the specified time, firstly the frequency that the ATtiny2313 is running at must be specified by defining it at the top of the C source file as shown above. Compiler optimization must be on for the function to generate the desired timing period.
What are the features of timer 2 in AVR?
Unlike other timers, TIMER2 offers us with a wide range of prescalers to choose from. In TIMER0/1 the prescalers available are 8, 64, 256 and 1024, whereas in TIMER2, we have 8, 32, 64, 128, 256 and 1024! Since we are choosing 256 as the prescaler, we choose the 7th option (110).
What is CTC mode?
In CTC mode the counter is cleared to zero when the counter value (TCNT2) matches the OCR2A. The OCR2A defines the top value for the counter, hence also its resolution. This mode allows greater control of the compare match output frequency. It also simplifies the operation of counting external events.