Device is secure. Erase to unsecure? why I meet this problem before CW debug on 82748

[terrybogard]

Dear NXP experts,

please help,

Device is secure. Erase to unsecure? why I meet this problem before CW debug on 82748. if I chose yes, the code in the flash will be erased, how can i connect 82748 without erase whole flash?

[xiangjun_rong]

Hi,

As you know that in secure mode, the JTAG port is blocked, customer can not use the JTAG to write or read. But there is a backdoor, the JTAG accepts only mass erasure command in secure mode so that customer can erase all flash in secure mode to protect the code while avoid the phenomenon that the chip flash can never be written once it is in secure mode.

Hope it can help you

BR

XiangJun Rong

[terrybogard]

why sometimes it will happen, and sometimes not? And how can I avoid device secure happen when program chip? 

[xiangjun_rong]

Hi,

I remember that the CW tools can generates the following array, and write it to configuration field in flas when you download code to flash.

But now I can not find it out.

BR

XiangJun Rong

#pragma define_section reserved_FCF "reserved_FCF.text" RX
#pragma section reserved_FCF begin
static const uint8_t _flash_config_field[] = {

/* NV_BACKKEY3: KEY=0xFF */ \
0xFFU, \
/* NV_BACKKEY2: KEY=0xFF */ \
0xFFU, \
/* NV_BACKKEY1: KEY=0xFF */ \
0xFFU, \
/* NV_BACKKEY0: KEY=0xFF */ \
0xFFU, \
/* NV_BACKKEY7: KEY=0xFF */ \
0xFFU, \
/* NV_BACKKEY6: KEY=0xFF */ \
0xFFU, \
/* NV_BACKKEY5: KEY=0xFF */ \
0xFFU, \
/* NV_BACKKEY4: KEY=0xFF */ \
0xFFU, \
/* NV_FPROT3: PROT=0xFF */ \
0xFFU, \
/* NV_FPROT2: PROT=0xFF */ \
0xFFU, \
/* NV_FPROT1: PROT=0xFF */ \
0xFFU, \
/* NV_FPROT0: PROT=0xFF */ \
0xFFU, \
/* NV_FSEC: KEYEN=1,MEEN=3,FSLACC=3,SEC=2 */ \
0x7EU, \
/* NV_FOPT: FOPT[7:6] = 11b means boot from ROM, other value means boot from Flash */ \
0xFFU, \
/* Reserved */ \
0xFFU, \
/* Reserved */ \
0xFFU
};
#pragma section reserved_FCF end