Identifier in the InfoPage??

RE: Identifier in the InfoPage??

Hung Bui — Thu, 06 Aug 2015 09:29:41 GMT

@Gustav: I haven't tested on SDCC, on Keil I have to set the Memory to Small, so that the variable will not be located in xdata, because the infopage will occupy the xdata address area when enabled.

Did it work for you in SDCC ?

RE: Identifier in the InfoPage??

Gustav — Thu, 06 Aug 2015 07:34:10 GMT

Dear Hung Bui,

Great work! Thanks a lot. I had to change it a bit to adapt to SDCC. The data has to be put into the destination array while INFEN == 0. I have always used Small Memory Model, but SDCC compiles the same .hex file, no matter if the model is small or not.

enter code here

void flash_read_chipID (uint8_t *dst, uint8_t n) { uint8_t i, j; volatile uint8_t __xdata *gzp = (uint8_t __xdata *)0x0b;// 0x0b is start of chip ID in info-page

F0= INFEN;

INFEN = 1;

for (i=0; i<n; i++) {
    j = *(gzp + i);
    INFEN = 0;
    dst[i] = j;// dst[i] has to executed while INFEN == 0
    INFEN = 1;
}
INFEN = F0;

}

RE: Identifier in the InfoPage??

Hung Bui — Wed, 05 Aug 2015 15:54:26 GMT

Hi Gustav,

Sorry for the mistake. I just checked again, actually only 5 bytes from 0x0b to 0x0f should be used as CHIP_ID. I attached in my answer the example project to read the Infopage. Note that you have to set Memory Model to Small.

RE: Identifier in the InfoPage??

Gustav — Wed, 05 Aug 2015 14:39:34 GMT

With nRFgo I have read 7 different nRF24le1 chips. I can see that the first few bytes of the infoPage are fixed and depend on the chip type. The last 7 bytes of the infoPage seems to be the only ones that are random. But this is still 2^(7*8) combinations. That is good enough for the product I am working on.

I have tried to read the infoPage using the MCU, but without any luck.

__xdata uint8_t p[32]
PCON |= PMW;

flash_bytes_read(0x0000, p, 32);
PCON &= ~PMW;

The array, p, is filled with bytes that does not look like the infoPage. The result is different, but still not good, if the PCON statements are removed (which they probably should).

Can you drop a few lines about how to read the infoPage from MCU.

RE: Identifier in the InfoPage??

Hung Bui — Wed, 05 Aug 2015 13:47:03 GMT

@Gustav: The Identifier is generated randomly when in production, not a unique number for each chip. So there is a chance that we have 2 devices with same identifier, but it's small, should be one in 2^40. The chip ID is from address 0x0B to 0x0F.

Yes you can read the identifier from MCU.

ReadInfoPage.zip