What is best/good way to create a small delay with LCMXO2-12

[LM]

I need a delay, lets say 10us. I could use a lot of counters to get it from clk, but there probably is a better solution already built in the chip/kit. And of course what is the signal name I can start dividing down to get that 1/10us.

This is quite basic question, so a Lattice forum would be a better place to ask this, but Lattice forums I could find were quite quiet. Is there a better place?

I'm having holiday and it rains, so I have time to test programming of the LCMXO2-1200ZE-B-EVN ev kit. But I have not EV kit yet. So it limits what I can do and what I know.

 

[Gabor]

LM wrote:

I need a delay, lets say 10us. I could use a lot of counters to get it from clk, but there probably is a better solution already built in the chip/kit. And of course what is the signal name I can start dividing down to get that 1/10us.

This is quite basic question, so a Lattice forum would be a better place to ask this, but Lattice forums I could find were quite quiet. Is there a better place?

I'm having holiday and it rains, so I have time to test programming of the LCMXO2-1200ZE-B-EVN ev kit. But I have not EV kit yet. So it limits what I can do and what I know.

You won't get delays of 10 microseconds without using a clock. The
MachXO2 doesn't necessarily need an external clock, but its internal
oscillator will not give you a very precise delay.

There are probably some simple demo designs shipped with the kit
that can help you generate a delay. Perhaps you can do it with
the Timer/Counter core instead of using the fabric to build
counters.

-- Gabor

 

[LM]

On Tuesday, July 17, 2012 4:33:45 PM UTC+3, Gabor wrote:

LM wrote:
I need a delay, lets say 10us. I could use a lot of counters to get it from clk, but there probably is a better solution already built in the chip/kit. And of course what is the signal name I can start dividing down to get that 1/10us.

This is quite basic question, so a Lattice forum would be a better place to ask this, but Lattice forums I could find were quite quiet. Is there a better place?

I'm having holiday and it rains, so I have time to test programming of the LCMXO2-1200ZE-B-EVN ev kit. But I have not EV kit yet. So it limits what I can do and what I know.


You won't get delays of 10 microseconds without using a clock. The
MachXO2 doesn't necessarily need an external clock, but its internal
oscillator will not give you a very precise delay.

I understand, but I would guess it has some dividers for that built in.

There are probably some simple demo designs shipped with the kit
that can help you generate a delay. Perhaps you can do it with
the Timer/Counter core instead of using the fabric to build
counters.

-- Gabor
Probably. I looked at some demo designs for ev kit. They were supposed to be in VHDL, but didn't look like it.

What is "Timer/Counter core". Where can I find it. I found the IPexpress in Lattice IDE. It has a counter defined but nothing with clock from internal signal. But so far this is best I can find.

 

[Gabor]

LM wrote:

On Tuesday, July 17, 2012 4:33:45 PM UTC+3, Gabor wrote:
LM wrote:
I need a delay, lets say 10us. I could use a lot of counters to get it from clk, but there probably is a better solution already built in the chip/kit. And of course what is the signal name I can start dividing down to get that 1/10us.

This is quite basic question, so a Lattice forum would be a better place to ask this, but Lattice forums I could find were quite quiet. Is there a better place?

I'm having holiday and it rains, so I have time to test programming of the LCMXO2-1200ZE-B-EVN ev kit. But I have not EV kit yet. So it limits what I can do and what I know.


You won't get delays of 10 microseconds without using a clock. The
MachXO2 doesn't necessarily need an external clock, but its internal
oscillator will not give you a very precise delay.

I understand, but I would guess it has some dividers for that built in.

There are probably some simple demo designs shipped with the kit
that can help you generate a delay. Perhaps you can do it with
the Timer/Counter core instead of using the fabric to build
counters.

-- Gabor
Probably. I looked at some demo designs for ev kit. They were supposed to be in VHDL, but didn't look like it.

What is "Timer/Counter core". Where can I find it. I found the IPexpress in Lattice IDE. It has a counter defined but nothing with clock from internal signal. But so far this is best I can find.

I would suggest looking at the MachXO2 family data sheet:

http://www.latticesemi.com/documents/38834.pdf

The Timer/Counter is a "hard" function, and may not be on all versions
of the MachXO2 family. All of them have the internal oscillator, though
and that does have some flexibility in frequency - the same as for
master mode configuration (it's the same oscillator). Still the
best bet for timing is usually an external crystal oscillator and
I'd be surprised if the eval board doesn't come with one.

-- Gabor