AM2431: OSPI0_RESET_OUT behavior

lance Forman

Part Number: AM2431
Other Parts Discussed in Thread: LP-AM243

i notice on some of the development boards the OSPI0_RESET_OUT signal is "ANDed" with MCU_RESETSTATz and sometimes it also "ANDed" with PORz_OUT.

It seems that those additional "AND" functions are not needed but I do not have a clear definition of OSPI0_RESET_OUT and when it is in RESET mode. If this could be explained would be helpful.

over 3 years ago

0 Mike Pridgen over 3 years ago

TI__Mastermind 22685 points

Hi,

The logic behind ANDing with the reset signals is to ensure the memory receives a reset before ROM execution tries to access it from OSPI boot code. Including the gpio pin ensures application code can reset the OSPI.

Regarding multiple reset signals, RESETSTATz is sufficient. I'm not sure which EVM schematic also includes the PORz signal, but on both the TMDS243GPEVM and LP-AM243, only the gpio ans RESETSTATz are ANDed together.

Thanks
Mike

0 lance Forman over 3 years ago in reply to Mike Pridgen

Intellectual 280 points

Thanks,

Is the behavior of OSPI0_RESET_OUT defined anywhere. for example during a warm reset does it go low? Is it the application code that strictly controls OSPI0_RESET_OUT or is there any hardware intervention?

0 Mike Pridgen over 3 years ago in reply to lance Forman

TI__Mastermind 22685 points

The OSPI reset line is controlled by the OSPI peripheral and its software drivers. If your OSPI device uses the reset line, the software should configure the module to assert reset during an SoC warm reset. If reset is not used, the pin is not asserted during an SoC warm reset.

Thanks,
Mike

0 lance Forman over 3 years ago in reply to Mike Pridgen

Intellectual 280 points

Thank You,

So if my Software configures the module to assert OSPI0_RESET_OUT (LOW) during a Warm Reset then it doesn't seem like I would also need RESETSTATz . Please confirm that.

thanks

0 lance Forman over 3 years ago in reply to lance Forman

Intellectual 280 points

Hi I was wondering if my last question has an answer

thanks

lance

0 Mike Pridgen over 3 years ago in reply to lance Forman

TI__Mastermind 22685 points

Hi lance,

Apologies for the slow response. The benefit of including RESETSTATz is that it ensure the OSPI module is reset and in a known state during reset or power on events other than a warm reset.

Thanks,
Mike

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AM2431: OSPI0_RESET_OUT behavior