LPC MicrocontrollersのトピックRe: LPC55S69 : flash prefetch bit is dropped after PowerDown

LPC55S69 : flash prefetch bit is dropped after PowerDown

EugeneHiihtaja — Thu, 30 Jan 2020 13:22:43 GMT

Hello !

I'm setting Flash prefetch bit for accelerate performance.

Testing show that it set to 0 while PowerDown mode.

Is this true ?

Before :

+SYSCON->FMCCR 0xB03A -> 150Mhz, prefetch ON

After:
-SYSCON->FMCCR 0x101A -> 12Mhz, prefetch OFF

Setting on FMCCCR in BOARD_BootClockFRO12M();

done in correct way.

Regards,

Eugene

Sabina_Bruce — Thu, 06 Feb 2020 15:52:08 GMT

Hi Eugene,

Could you please confirm the revision of your LPC55S69?

Can you please clarify what testing is done?

Testing show that it set to 0 while PowerDown mode.

Best Regards,

Sabina

EugeneHiihtaja — Fri, 07 Feb 2020 08:25:23 GMT

Everything is latest. Board revision A2.

When prefecth is enabled it is +25% gain in performance of software cryptography tests.

So prefecth is working if it enabled.

Regards,

Eugene