BQ78Z100: Unseal over HDQ

Steve Widener

Genius 11010 points

Part Number: BQ78Z100

What are the steps to unseal the BQ78Z100 over HDQ? Are there any timing constraints?

over 4 years ago

0 Wyatt Keller over 4 years ago

TI__Guru** 105590 points

Hello Steve,

The unseal procedure will be the same timing requirements as I2C.

You can check this other thread regarding the procedure and timing requirement: e2e.ti.com/.../595487

Sincerely,

Wyatt Keller

0 Steve Widener over 4 years ago in reply to Wyatt Keller

TI__Genius 11010 points

We don’t have the keys and AltManufacturerAccess() 0x0035 Security Keys command is not available when the gauge is sealed. Thus we need these key to try unseal the gauge.

0 Kang Kang over 4 years ago in reply to Steve Widener

TI__Mastermind 24870 points

Hello Steve,

That's not something TI provides. That's set by the pack maker or customer.

Thanks!

0 Steve Widener over 4 years ago in reply to Kang Kang

TI__Genius 11010 points

Let’s say that our keys are:

Unseal Ukey1 = 0x1234 Ukey2 = 0x5678

Full access FAkey1= 0x9abc FAkey2= 0xdef0

and we want to unseal a battery so sequence of bytes should be like this

<0x3E | 0x80> <0x34> <0x12> <- the first unseal key, Ukey1

<0x3E | 0x80> <0x78> <0x56> <- the second unseal key, Ukey2

Where 0x80 is the 1-bit R/W field.

Is it true?

0 Wyatt Keller over 4 years ago in reply to Steve Widener

TI__Guru** 105590 points

Hello Steve,

You do not need to OR the MAC command with 0x080, it is correct what you have if you remove the 0x80. The read/write is done within the address of the gauge, so 0xAA is write, 0xAB is read.

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ78Z100: Unseal over HDQ