Realize a 1 micro second hardware timer

Christoph Obrecht

Other Parts Discussed in Thread: AM3359

I need for a timestamp module, a 1 micro second timer. I found in timer register only a prescaler (2n division ratio) register for the timer clock not a prescale-counter register. (like in C2000 series)

Everybody have a idea for me?

It is not convenient to use a 600MHz or 800MHz counter and recalculate the value to a 1MHz counter, because timing and overflow. And I wouldn’t like a interrupt every 1 micro second.

I use a Sitara AM3359 with 600 or 800MHz system clock.

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi Cristoph,

Have you considered using the PRU for this? It runs off a 200MHz clock and is completely independent.

0 Christoph Obrecht over 10 years ago in reply to Biser Gatchev-XID

Prodigy 220 points

That is a possibility, but I use the PRU for etherCAT, too.

Isn't there a simpler solution?

0 Matthijs van Duin over 10 years ago

Mastermind 8040 points

Note that the timers do not run on the cortex-a8 clock but (by default) on the main osc. Assuming a 24 MHz osc and a /8 timer prescaler, you only need to divide a count by 3 to convert to microseconds (a decent compiler will generate a 4-instruction sequence for that).

0 Christoph Obrecht over 10 years ago in reply to Matthijs van Duin

Prodigy 220 points

That is a good information.
My oscillator clocked with 25MHz.

OK, important for me is the conclusion, the timer module isn't able to configure as a 1MHz counter.

Thanks

0 Matthijs van Duin over 10 years ago in reply to Christoph Obrecht

Mastermind 8040 points

No, unless you provide an 1 MHz signal at TCLKIN

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Realize a 1 micro second hardware timer