Datasheet

 2015 Microchip Technology Inc. Preliminary DS60001320B-page 67
PIC32MZ Embedded Connectivity with Floating Point Unit (EF) Family
4.1.1 BOOT FLASH SEQUENCE AND
CONFIGURATION SPACES
Sequence space is used to identify which boot Flash is
aliased by aliased regions. If the value programmed
into the TSEQ<15:0> bits of the BF1SEQ0 word is
equal to or greater than the value programmed into the
TSEQ<15:0> bits of the BF2SEQ0 word, Boot Flash 1
is aliased by the lower boot alias region, and Boot
Flash 2 is aliased by the upper boot alias region. If
TSEQ<15:0> bits of BF2SEQ0 is greater than
TSEQ<15:0> bits of BF1SEQ0, the opposite is true
(see
Table 4-2 and Table 4-3 for BFxSEQ0 word
memory locations).
The CSEQ<15:0> bits must contain the one’s
complement value of the TSEQ<15:0> bits; otherwise,
the value of TSEQ<15:0> is considered invalid, and an
alternate sequence is used. See
Section 4.1.2
“Alternate Sequence and Configuration Words” for
more information.
Once boot Flash memories are aliased, configuration
space located in the lower boot alias region is used as
the basis for the Configuration words, DEVSIGN0,
DEVCP0, and DEVCFGx (and the associated alternate
configuration registers). This means that the boot Flash
region to be aliased by lower boot alias region memory
must contain configuration values in the appropriate
memory locations.
4.1.2 ALTERNATE SEQUENCE AND
CONFIGURATION WORDS
Every word in the configuration space and sequence
space has an associated alternate word (designated by
the letter A as the first letter in the name of the word).
During device start-up, primary words are read and if
uncorrectable ECC errors are found, the BCFGERR
(RCON<27>) flag is set and alternate words are used.
If uncorrectable ECC errors are found in primary and
alternate words, the BCFGFAIL (RCON<26>) flag is
set and the default configuration is used.
Note: Do not use word program operation
(NVMOP<3:0>
= 0001) when program-
ming data into the sequence and
configuration spaces.