LMX2492EVM: How to use USB2ANY and TICS PRO to trigger LMX2492EVM

Hi Zhu,

TRIG and MOD control from TICS Pro is here:

Did you mean you have checked the box but the pin did not turn HIGH?

Thanks for your reply.

Today I have a other test.

Set "TRIG1_MUX"="“input= TRIGER1”  TRIG1_PIN=INPUT

Set "MOD_MUX"=OUTPUT TRIGA MOD_PIN=Output_PP

I use a oscilloscope to monitor  at TP_TRIG1 (R66) , when I check and uncheck "Program Pins " "TRIG1",the oscilloscope  shows the TTL up and down, it seems ok and this pin was controlled.

then, I set oscilloscope to monitor  at TP_MOD (R71) --Ouput trigAand set RAMP  caculator again , the simplest example :Continuous Sawtooth Ramp Example.

but when I check and uncheck   "Program Pins " "TRIG1",the oscilloscope  shows TP_MOD ---TriggerA  is NO TTL signal， so there is no LFM signal generated.

I want to kwnow there is some thing wrong in my software setting?

thanks.

when I set MOD_MUX=OUTPUT TRIG1 ,the oscilloscope   monitor in TP_MOD has TTL signal  when I check and uncheck   "Program Pins " "TRIG1".

so this pin is ok and NO physical damage.

oscilloscope  captured the OUTPUT TRIGA,  a 20ns width pulse when I check and uncheck "Program Pins " "TRIG1".  but there was also no LFM  output.  only a CW instead.

Hi Zhu,

can you try below?

I expect the timing diagram will be as follows:

hello ,thanks for your reply. I think maybe I find the reason: the Triger_1 from USB2ANY uWire pin only change once when I check and uncheck  "Program Pins " "TRIG1" , so there only one LFM signal at once.  Due to the short time of waveform（only 100us and only once ），my spectrum analyzer and my eyes cannot capture them.

Today I use a function generator to generate a 3.3V TTL continuous square  wave, then, the spectrum analyzer  with "Trace MAX hold" can capture them.

So I wanna to ask a other question:

How to generate a frame LFM pulse （such as 128 or 256 LFM）by ONE trigger？

How to use and set  "Rampcount" to get a frame? I set it as 128 but it seems not work.

thanks

I have search in this forums and find similar question LMX2492: how to use the LMX2492 ramp count function? - Clock & timing forum - Clock & timing - TI E2E support forums. 

I try to follow that issue.

first I use this setting , but when a check and uncheck  "Program Pins " "TRIG1"  only one chirp come out.

then, I use other setting like this 

the oscilloscope  captured all the trigA/flg0/trigB signal 

but there is only ONE LFM signal  :by using spectrum analyzer monitor at 9625MHz SPAN=0Hz as time domain and trigger by Video  ,only one signal after I check and uncheck "Program Pins " "TRIG1"  , not 16 sequences

I think maybe something wrong with my TICS Pro setting ,not hardware fault.

could you help me?

thanks

Hi Zhu,

I don't have lab access at the moment, please verify if below works:

Hi ,thanks your reply.

I tried this setting, Its seems the EVM can generate ramp count after one TTL trigger from trig1(TRIGA). 

however,  due to I check the "RAMP_AUTO"， it seems " Automatically clear RAMP_EN when RAMP Count hits terminal count"（from datasheet pp25 Table 8). the next TTL trigger cannot repeatedly  generate  LFM frame again .so I need to manual check and uncheck “Ramp Enable” to generate next frame.

Should  I need to use this sequential in my embeded code to repeatedly  generate  LFM frame ?

1) setting every registers about RF/RAMP/ trigger parameters

2) set RAMP_AUTO R84[5] register as 1 for enable Automatically clear

3) set RAMP_EN R58[8] as 1 for enable RAMP

4) give TTL trigger to LMX2492 to generat LFM chirp count sequnces.

5）use some flag signal to trigger ADC  sampling

6）after all sampling  , go to 3) set RAMP_EN R58[8] =1  again to next sequnces

Is it ok?  or  there is other simpler method？

thanks

Hi Zhu,

with my configuration, did you get 16 sawtooth waveforms? You can use a scope to probe the Vtune pin of the VCO to verify.

It would be helpful if you could include TRIG1 in the measurement. Something like below:

I test it  the scope like this below.

I think the Ramp 0 （CW 100us  ） disappeared  ,only  show at beginning and end .

I test it  the scope like this below.

I think the Ramp 0 （CW 100us  ） disappeared  ,only  show at beginning and end .

I tried different setting combination but It seems not work as I want.

pls see the attachment

新建 Microsoft Word 文档.pdf

Hi zhu,

I will take a look later today.

Hi，dear Mr. Noel. I tried again and again but no result.

did you have any other suggestion?

thanks.