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NUC126
Aug. 08, 2018
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Rev 1.03
NUC12
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System Memory Map without IAP mode
In system memory map without IAP mode, the system memory vector mapping is not supported. There
are two kinds of system memory map without IAP mode when chip booting. One is LDROM without
IAP, the other one is APROM without IAP.
In LDROM without IAP mode, LDROM base is mapping to 0x0000_0000. CPU cannot
read or execute code from APROM. In other words, APROM is absent in the system
memory map of LDROM without IAP.
In APROM without IAP mode, APROM base is mapping to 0x0000_0000. CPU cannot
read or execute code from LDROM. In this mode, LDROM is absent for current system
memory map. Just as IAP mode, the Data Flash is shared with APROM and the Data
Flash base address is defined by CONFIG1. Therefore, in APROM without IAP mode, we
still can use Data Flash function.
0x0000_0000
0x0003_FFFF
APROM without IAP mode
0x0000_0FFF
LDROM without IAP mode
Application ROM
(APROM)
Data Flash
SPROM
DFBA
0x0020_07FF
0x0020_0000
User Config
Loader ROM
(LDROM)
SPROM
User Config
0x0030_0000
Figure 6.4-8 System Memory Map without IAP mode
6.4.4.2
Boot Selection
The NUC126 series provides four booting sources for user to select, including LDROM with IAP,
LDROM without IAP, APROM with IAP and APROM without IAP. The booting source and system
memory map are setting by CBS (CONFIG0[7:6]). The vector mapping function only supported in IAP
mode, i.e, APROM with IAP and LDROM with IAP.
CBS[1:0]
Boot Selection/System Memory Map
Vector Mapping Supporting
00
LDROM with IAP
Yes
01
LDROM without IAP
No
10
APROM with IAP
Yes