MPC5xxx中的主题 Re: CMU CLKMN1

CMU CLKMN1

Amr_Awny — Tue, 26 Apr 2022 21:54:46 GMT

My first Question:

Shall I configure CMU_3 to monitor the ADC on the max value given in the below table ,and Shall I consider the frequencies below in all CMUs.

I did so in the HFREF and LFREF

=80Mhz*16*4/16Mhz =320

LFREF = 320*0.95 = 304 --> 0x130

HFREF = 320*1.05 = 336 --> 0x150

if this is correct how shall I test this implementation?

I have added an ADC and tried to change the LFREF and HFREF to other values in order for the CMU to write 1 to CMU_ISR[OLRI] but it failed to do it.

Is there any other configuration to be done?

the configuration that I have done
CME -> CLKMN1 monitor enable. to 1
RCDIV->CLKMT0_RMN division factor. to 11
CKSEL1 -> CLKMT0_RMN is selected to 11
LFREF = 320*0.95 = 304 --> 0x130
HFREF = 320*1.05 = 336 --> 0x150

Re: CMU CLKMN1

PetrS — Thu, 28 Apr 2022 11:26:17 GMT

Hi,

CLKMN0_RMT monitor is only implemented on CMU0, so on CMU3 just LFREF, HFREF and CME can be written, also only FLL, FHH flags can be set.

Calculation is correct, so be sure selected clock in MC_CGM_AC0 is enabled in MC_ME and MC_CGM_AC0_DC2 divider is enabled. With divider you can also test low freq reference.

BR, Petr

Re: CMU CLKMN1

Amr_Awny — Thu, 05 May 2022 10:36:32 GMT

Thank you for your reply,

I have enabled the MC_CGM_AC0_DC2 divider and read the MC_CGM_AC0=0x0400 0000, however, the CMU_ISR register is fetching the same value written in the CMU_CSR register

Re: CMU CLKMN1

PetrS — Thu, 05 May 2022 12:11:07 GMT

Hi,

if you increase AC0_DC2 divider, will a low reference flag be set?

BR, Petr

Re: CMU CLKMN1

Amr_Awny — Sun, 08 May 2022 14:49:46 GMT

how to enable the in MC_CGM_AC0 is enabled in MC_ME ?

Re: CMU CLKMN1

PetrS — Mon, 09 May 2022 08:02:25 GMT

you need to select clock source in MC_CGM.AC0_SC and then enable divider MC_CGM.AC0_DC2 (set DE bit and DIV)

BR, Petr

Re: CMU CLKMN1

Amr_Awny — Wed, 11 May 2022 16:01:00 GMT

Yes, it changes, however Now I have another Issue,

In CMU0, CMU3, CMU4

the ISR of each fire 0x02, FLLI

What are the values should be written in their division register in order to clear the ISR FLLI bit

CMU0

=160Mhz*16*4/16Mhz =640

LFREF = 640*0.95 = 608 --> 0x260

HFREF = 800*1.05 = 672 --> 0x2A0

MC_CGM_AC0_DC0=0x80010000

CMU3

=80Mhz*16*4/16Mhz =320

LFREF = 320*0.95 = 304 --> 0x130

HFREF = 320*1.05 = 336 --> 0x150

MC_CGM_AC0_DC2 = 0x80000000

CMU4

=80Mhz*16*4/16Mhz =320

LFREF = 320*0.95 = 304 --> 0x130

HFREF = 320*1.05 = 336 --> 0x150

MC_CGM_AC1_DC1= 0x80000000

Re: CMU CLKMN1

Mennazz — Tue, 18 Mar 2025 14:54:33 GMT

having the same issue @PetrS