What is "Bad Device Reset" ?

Unknown Unknown86

Prodigy 170 points

I'm wondering what is "Bad Device Reset" ? Described (barely) in AM335x TRM section 8.1.7.3.3 (SPRUH73K).

I searched the document for "DEVICE_TYPE" and found nothing! I think it might have something to do with ROM Code.

Regards

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi Saman,

As section 8.1.7.3.3 says, Bad Device Reset is asserted whenever the DEVICE_TYPE encodes an unsupported device type, such as the code for a "bad" device. DEVICE_TYPE is taken from the DEVTYPE bitfield in the control_status register (TRM section 9.3.1.4).

0 Unknown Unknown86 over 10 years ago in reply to Biser Gatchev-XID

Prodigy 170 points

Thanks. I want to know what is DEVTYPE and when it will be encoded as "bad" device?
What fills devtype in control_status Register? and it has only one type, General Purpose (GP) Device!

0 Biser Gatchev-XID over 10 years ago in reply to Unknown Unknown86

TI__Guru**** 393215 points

Yes, any value different from General Purpose (GP) Device type will trigger a bad device reset. This would mean the device is defective. Value is factory programmed and cannot be modified.

0 Unknown Unknown86 over 10 years ago in reply to Biser Gatchev-XID

Prodigy 170 points

Thanks again.
You sure it's factory programmed ? As section 9.2.4.1 says, The CONTROL_STATUS register reflects the system boot and the device
type configuration values as sampled when the power-on reset (PORz) signal is asserted.
And what is General Purpose (GP) Device?

0 Biser Gatchev-XID over 10 years ago in reply to Unknown Unknown86

TI__Guru**** 393215 points

Yes I am sure. All AM335X processors are GP devices.

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What is "Bad Device Reset" ?