
UM10800
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© NXP Semiconductors N.V. 2016. All rights reserved.
User manual
Rev. 1.2 — 5 October 2016
365 of 487
NXP Semiconductors
UM10800
Chapter 24: LPC82x Flash controller
24.4.2 Flash signature start address register
24.4.3 Flash signature stop address register
24.4.4 Flash signature generation result register
The signature generation result register returns the flash signature produced by the
embedded signature generator.
The generated flash signature can be used to verify the flash memory contents. The
generated signature can be compared with an expected signature and thus makes saves
time and code space. The method for generating the signature is described in
24.5 Functional description
24.5.1 Flash signature generation
The flash module contains a built-in signature generator. This generator can produce a
32-bit signature from a range of flash memory. A typical usage is to verify the flashed
contents against a calculated signature (e.g. during programming).
The address range for generating a signature must be aligned on flash-word boundaries,
i.e. 32-bit boundaries. Once started, signature generation completes independently. While
signature generation is in progress, the flash memory cannot be accessed for other
purposes, and an attempted read will cause a wait state to be asserted until signature
Table 305. Flash Module Signature Start register (FMSSTART, 0x4004 0020) bit description
Bit
Symbol
Description
Reset
value
16:0
START
Signature generation start address (corresponds to AHB byte
address bits[18:2]).
0
31:17
-
Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined.
NA
Table 306. Flash Module Signature Stop register (FMSSTOP, 0x4004 0024) bit description
Bit
Symbol
Value
Description
Reset
value
16:0
STOPA
Stop address for signature generation (the word
specified by STOPA is included in the address range).
The address is in units of memory words, not bytes.
0
30:17
-
Reserved, user software should not write ones to
reserved bits. The value read from a reserved bit is not
defined.
0
31
STRTBIST
When this bit is written to 1, signature generation starts.
At the end of signature generation, this bit is
automatically cleared.
0
Table 307. FMSW0 register bit description (FMSW0, address: 0x4004 002C)
Bit
Symbol
Description
Reset value
31:0
SIG
32-bit signature.
-