UM10429
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© NXP B.V. 2010. All rights reserved.
User manual
Rev. 1 — 20 October 2010
172 of 258
NXP Semiconductors
UM10429
Chapter 17: LPC1102 Flash memory programming firmware
After signature generation, a 128-bit signature can be read from the FMSW0 to FMSW3
registers. The 128-bit signature reflects the corrected data read from the flash. The 128-bit
signature reflects flash parity bits and check bit values.
Content verification
The signature as it is read from the FMSW0 to FMSW3 registers must be equal to the
reference signature. The algorithms to derive the reference signature is given in
.
Fig 33. Algorithm for generating a 128 bit signature
sign = 0
FOR
address = FMSTART.FMSTART
TO
FMSTOP.FMSTOP
{
FOR
i = 0
TO
126
nextSign[i] = f_Q[address][i]
XOR
sign[i+1]
nextSign[127] = f_Q[address][127]
XOR
sign[0]
XOR
sign[2]
XOR
sign[27]
XOR
sign[29]
sign = nextSign
}
signature128 = sign