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P4080 Development System User’s Guide, Rev. 0
Freescale Semiconductor
17
Architecture
•
PromJet
Local bus chip select routing is summarized in this table. The “cfg_lbmap” column is used to rearrange
the internal addresses of NOR Flash devices, based on user configuration options. Simplistically, no matter
what state the switches are in, the end-user toggling the switch results in toggling the halves or quarters of
the NOR Flash and toggling the CS lines of the NAND Flash. If different program images are stored
therein, upon reset, different startup code is executed. NAND Flash is not currently supported on the
system board. The current hardware implementation is not correct, but the future system board re-spin may
incorporate a correct and supported implementation.
Table 7. Local Bus Chip Select Mapping
Flash
Selection
cfg_lbmap
(0:3)
NOR
Flash
PromJet
NAND Flash
ngPIXIS
Description
0000
LCS0
LCS1
LCS[2,4:6]
Boot from NOR Flash region #0
0001
LCS0
LCS1
LCS[2,4:6]
Boot from NOR Flash region #1
0010
LCS0
LCS1
LCS[2,4:6]
Boot from NOR Flash region #2
0011
LCS0
LCS1
LCS[2,4:6]
LCS3
Boot from NOR Flash region #3
0100
LCS0
LCS1
LCS[2,4:6]
Boot from NOR Flash region #4
0101
LCS0
LCS1
LCS[2,4:6]
Boot from NOR Flash region #5
0110
LCS0
LCS1
LCS[2,4:6]
Boot from NOR Flash region #6
0111
LCS0
LCS1
LCS[2,4:6]
Boot from NOR Flash region #7
1000
LCS1
LCS0
LCS[2,4:6]
—
Boot from PromJet, NOR Flash unbanked.
1001
LCS2
LCS1
LCS[0,4:6]
—
Boot from NAND Flash NOR Flash unbanked.
1010–1111
Not valid