AM335x GP EVM not reacting to SYSboot pins

K Md Feroz Irfan

Hi Champs,

My EVM has some issues with the SD boot mode. So I am trying to boot it up via Nand. However while trying to connect to the CCS the OnTargetConnect gel function is hanging for ever. I tried resetting the SYSBOOT pins 14:15 however no change in the below error message. Input frequency is still 25 MHz!

CortxA8: Output: **** AM335x 15x15 EVM Initialization is in progress ..........
CortxA8: Output: **** AM335x ALL PLL Config for OPP == OPP100 is in progress .........
CortxA8: Output: Input Clock Read from SYSBOOT[15:14]: 25MHz
CortxA8: Output: **** AM335x PLL Config failed!! Check SYSBOOT[15:14] for proper input freq config
CortxA8: Output: **** AM335x DDR2 EMIF and PHY configuration is in progress...
CortxA8: Output: EMIF PRCM is in progress .......

Can you please help?

Is there any other way I can flash the nand - UART?

Best Regards

Feroz

over 12 years ago

0 Biser Gatchev-XID over 12 years ago

TI__Guru**** 393215 points

Hi Feroz,

The AM335X EVM frequency is 24MHz (SYSBOOT[15:14]=01b).

Best Regards

Biser

0 K Md Feroz Irfan over 12 years ago in reply to Biser Gatchev-XID

TI__Expert 7225 points

Hi Biser,

Thanks.

I am not able to set it changing the SYSboot pins on the EVM SW4 switch! That is the problem.

Gel file function getInputFreqeuncy always gets value of 25MHz. I hacked the code in the gel fucntion to get 24MHz, however I see that

it hangs again on targetConnect at

<< Nothing happens>>

Any clues.... seems like some wierd issue! isn't it?

Best Regards

Feroz

0 Biser Gatchev-XID over 12 years ago in reply to K Md Feroz Irfan

TI__Guru**** 393215 points

Could the SW4 switch be broken? Strange...

Biser

0 John Murphy1 over 12 years ago in reply to Biser Gatchev-XID

Expert 1210 points

Please can you check the resistance of each switch (i.e. all 16) on SW3 and SW4 with the EVM powered off. It should be zero ohms when set to "ON", and open circuit when set to "OFF". I have noticed that the resistance is wrong on my EVM!

Perhaps there is a issue with SW3 and SW4?

0 Biser Gatchev-XID over 12 years ago in reply to John Murphy1

TI__Guru**** 393215 points

Hi John,

This is partly correct. Impedance across the switch itself should be zero when switch is closed. When swich is open you will get a non-zero (but not open circuit) reading, because there are 100kOhm pullups and 10kOhm pulldowns connected to opposite sides of the swich, which close the circuit via the power planes.

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AM335x GP EVM not reacting to SYSboot pins