Secrect key of MPC5606B

[shiyinbiao]

      Can you tell me something details or give me some documents about the secret key of MPC5606B. There is not too much introductions about the secret key in datasheet, and I want to know how and when  the secret key should be Writen.

      If I configure register donot write secrect key,after system carry out a period of time write, whether this configuration is effective?

      Or, If I configure register A and donot write its secrect key, then, I configured register B and write B's secrect key,after a period of time I write A's secrect key,whether A's configuration is effective?

[lukaszadrapa]

Hi,

first, there's no CSE module on MPC5606B. It's only on MPC5646B/C.

SECRET_KEY is a random number programmed in factory and it remains a secret forever. There's no way to read this number and user can't change the number.

Regards,

Lukas

[shiyinbiao]

Hi,

I know you mean, but I just want to find out the consequences of don't write SECRECT_KEY after configuring register.

like this:

 void Init_Wake_Up_Inputs(void)
{
SIU.PCR[64].R = 0x103;
WKUP.WIPUER.R = 0x0003ffff; 
WKUP.WISR.R = 0x00000008; 
WKUP.WRER.R = 0x00000008;
WKUP.WIREER.R = 0x00000008; 
WKUP.WIFEER.R = 0x00000008; 
WKUP.WIFER.R = 0x00000008; 

/*have not written SECRECT_KEY after configuring a module's  register*/
}

and this:

ME.STOP0.B.PDO = 1; 
ME.STOP0.B.MVRON = 0; 
ME.STOP0.B.DFLAON = 1; 
ME.STOP0.B.CFLAON = 1; 
ME.STOP0.B.FMPLLON = 0; 
ME.STOP0.B.FIRCON = 0; 
ME.STOP0.B.FXOSC0ON = 0;
ME.STOP0.B.SYSCLK = 0x02; 
ADC_0.MCR.B.PWDN = 1;
ME.STOP0.B.PDO = 1; 
ME.MCTL.R = 0xA0005AF0; 
ME.MCTL.R = 0xA000A50F;

/*have written SECRECT_KEY after configuring a module's register*/
while (ME.GS.B.S_MTRANS){}; 

[lukaszadrapa]

Hi,

I can understand now. The SECRET_KEY is something different - it is used on Cryptographic Services Engine module.

You are talking about Control key or just about key.

The Control key which is written to ME_MCTL register is used just for Mode Entry module to start mode transition. It is not needed to do something similar for other configurations like configuration of SIU module or WKPU module or whatever...

The RM says: " In order to change mode, the ME_MCTL register must be written with the correct value in the KEY field and then again with the correct "inverted key" value."

If you do not write the ME_MCTL as described (when you write the register only 1x, for example) then the mode transition will not start.

Regards,

Lukas

[shiyinbiao]

It's very kind of you, I apologise for the mistake I expressed.

Your answer is very helpful to me.

Thank you very much.