topic Re: LPC54114: what's the maximum CPU speed? in LPC Microcontrollers

LPC54114: what's the maximum CPU speed?

carlobramini — Wed, 21 Apr 2021 08:25:04 GMT

Hello,
I'm using an OM13089 LPCXpresso5411x and I would like to push the CPUs to their maximum speed.
Unfortunately, I'm a bit confuse because:
1) the datasheet "Rev. 2.6 - 3 September 2020" says that the maximum speed is 150MHz.
2) The user's manual UM10914 "Rev. 2.0 - 9 May 2018" says that the maximum speed is 100MHz.
3) if I try to set something faster than 120MHz with mcuxpresso_v3.01.000 libraries, the M4 goes in Hardware Fault exception.

What's the real maximum speed and how to set it?

Sincerely.

Re: LPC54114: what's the maximum CPU speed?

frank_m — Wed, 21 Apr 2021 08:35:45 GMT

> 1) the datasheet "Rev. 2.6 - 3 September 2020" says that the maximum speed is 150MHz.
> 2) The user's manual UM10914 "Rev. 2.0 - 9 May 2018" says that the maximum speed is 100MHz.

The MCU version might have changed in the meantime, perhaps check the schematics.

> if I try to set something faster than 120MHz with mcuxpresso_v3.01.000 libraries, the M4 goes in Hardware Fault exception.

Flash interface settings are tightly related to core speed. The higher the core clock, the more wait states you will need for the slower Flash. Too tight setting will lead to crashes and hardfaults.

You might need to check the MCU user manual, and change your SDK example accordingly.

I rarely mess with the core clock settings, haven't done it myself on a LPC.

Re: LPC54114: what's the maximum CPU speed?

Alice_Yang — Thu, 22 Apr 2021 09:29:22 GMT

Hello carlobramini,

How about use MCUXpresso config tool configure clock , then just test a hello world demo ?

Alice

Re: LPC54114: what's the maximum CPU speed?

carlobramini — Thu, 29 Apr 2021 09:47:03 GMT

Hello, thank you very much for the replies.

I tried to use MCUXpresso config tool and I have set 150MHz: I think it is working fine, although the CYCCNT register of DWT is not counting at that rate but MUCH slower. Then, I compared the sources of mcuxpresso_v3.01.000 libraries with the SDK_2.8.2_LPCXpresso54114 and I adjusted the function for setting the wait states of the flash, which was wrong according to the datasheet. Unfortunately, mcuxpresso_v3.01.000 libraries cannot still setup 150MHz... with the same parameters, it still goes to hardware fault. The only piece of code that I could not verify are differences between the function Chip_POWER_SetVoltage and POWER_SetVoltageForFreq, but unfortunately, there are not the sources for that. Since this is the only thing that I could not verify, I suspect that the bug could be there, if that function could not set up for 150MHz. Before giving up, I will try to import libpower.a from SDK to LPCOpen, to see if it will work.

Sincerely.

Re: LPC54114: what's the maximum CPU speed?

carlobramini — Fri, 30 Apr 2021 12:44:17 GMT

Hello,

I would like to confirm that importing CLOCK_SetupFROClocking() and POWER_SetVoltageForFreq() from SDK 2.9.0 to mcuxpresso_v3.01.000 libraries seems to have solved the problem and now I can setup clock speed up to 150MHz.

So, the bug seems to be restricted to libpower library into functions Chip_POWER_SetVoltage() and Chip_POWER_SetFROHFRate().

Sincerely.