LPC Microcontrollers中的主题 Re: Does the LPC1817 have a RNG?

Does the LPC1817 have a RNG?

josvisser — Thu, 24 May 2018 08:38:08 GMT

I know that LPC1817 does not have AES on chip, but does it have a True Random Number Generator?

Re: Does the LPC1817 have a RNG?

victorjimenez — Mon, 28 May 2018 15:25:15 GMT

Hello Jos,

According to the user manual (UM10430.pdf) page 14 the RNG is only available for the LPC18Sxx parts only.

Hope it helps!

Victor.

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Re: Does the LPC1817 have a RNG?

josvisser — Mon, 28 May 2018 16:04:58 GMT

Application note AN11643 describes RNG using the Keil MCB1800/4300 Evaluation Board, which has an LPC1857.

Is this an exception?

I only have an LPCXpresso 18S37 for evaluation, but my target is LPC1817.

Re: Does the LPC1817 have a RNG?

victorjimenez — Tue, 29 May 2018 17:36:35 GMT

Hello Jos,

You are right, in the application note that you mentioned is using LPC1800/LPC4300. The information regarding the RNG is kind of confusing. I already report this issue.

To know what information was right if the one in the application note or the one in the datasheet. I modified the example misc_otp_funcs provided in the LPCOpen 2_19 for the LPC4337. I used the evaluation board OM13076 with the LPC4367 to tried this.

At the end I found out that the application note is right, the LPC4300/LPC1800 does have a RNG. Please see image attach to see the results of the program I made to test this. I ran the example three times to be sure that I was getting different random values each time.

Hope it helps!

Victor.

Re: Does the LPC1817 have a RNG?

jamestasker — Thu, 19 Jul 2018 21:58:23 GMT

Hi Victor,

Would it be possible for you to post the code snippet you used to call the genRand() function and then read that random number? I'm trying to use the otp_genRand function to produce an IV, but I cannot seem to read it out properly. Thanks in advance.

Re: Does the LPC1817 have a RNG?

bernhardfink — Fri, 20 Jul 2018 12:13:47 GMT

If I remember correctly, on low level the RNG is quite easy to handle. I attached a project from the past, but I need to admit that I didn't test it before attaching it.

Regards,

Bernhard.

Re: Does the LPC1817 have a RNG?

josvisser — Fri, 20 Jul 2018 12:25:52 GMT

Thanks all for solving this out.

Regards,

Jos