Daniel Flor

MCP5606B JTAG reading

Discussion created by Daniel Flor on Oct 16, 2017
Latest reply on Oct 24, 2017 by Peter Vlna

I'm using MPC5606B and I would like to know what kind of issues I would have, concerning protection\encryption if I tried to read its flash content by JTAG using an external device.

I was able to read the MPC's flash content using a tool (UPA) and a PC, however, I want to do it by my own, using my own embedded hardware without the PC's tool. So, I studied about JTAG standard( JTAG_IEEE-Std-1149.1-2001 ), and about TAP controller state diagram. In order to better understand the JTAG reading, I Used the PC's tool to read the MCP's flash and an osciloscope to see how the communication is performed between the tool and MCP5606B.

I could see that it enters in the TAP controller state machine, The tool writes IR ( 0b00011 )and after that reads DR ( 0x2AE4301D ) and there is a lot of more communication that I didn't recognize yet, but, I know that the readed value 0x2AE4301D is the IDCODE of JTAG's MCP5606BF.

After to study Chapter five of MPC5606's reference manual, I expected that the tool would send a 64-bits password, but I didn't found it in communication yet ( the time of communication is too big, almost 10s ).

So I was wondering, how is performed the reading of the flash memory content, and how it is related to Censorship at bootloader?

 

With my bests regards,

Daniel.

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