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P4080 Development System User’s Guide, Rev. 0
18
Freescale Semiconductor
Architecture
The “address toggle” feature mentioned in
is implemented as multistaged XOR gate in-line with
the most significant addresses of the Flash, as shown in this figure.
Figure 10. Flash Address Toggle
When LBMAP encoded bits A23–A25 of the Flash address are altered (toggled), as shown in
, the
Flash behaves normally or is swapped around as virtual banks. Thus, the boot bank can be swapped around
to support up to eight boot images with or without RCW.
NORFlash
P4080
A-Latched
A[23:25]
A[0:22]
A[7:5]
ngPIXIS
LBMAP(0:3)
A[30:8]
via vbank pins