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M451
May. 4, 2018
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Boot Selection
6.4.4.2
The NuMicro
®
M451 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]).
LDROM with IAP
LDROM with IAP
CBS[1:0]
00
Controlled by CONFIG0
Boot Source
01
10
11
LDROM without IAP
LDROM without IAP
APROM with IAP
APROM with IAP
APROM without IAP
APROM without IAP
Figure 6.4-8 Boot Source Selection
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
11
APROM without IAP
No
Table 6.4-1 Vector Mapping Supporting
In-Application-Programming (IAP)
6.4.4.3
The NuMicro
®
M451 Series provides In-Application-Programming (IAP) function for user to switch
the code executing between APROM and LDROM. User can enable the IAP function by booting
chip and setting the chip boot selection bits in CBS (CONFIG0[7:6]) as 10 or 00.
When chip boots with IAP function enabled, any executable code (align to 512 bytes) is allowed to
map to the system memory vector any time. User can change the remap address to
FMC_ISP
ADDR and then trigger ISP procedure with the “Vector Remap” command.
In-System-Programming (ISP)
6.4.4.4
NuMicro
®
M451 series supports In-System-Programming (ISP) function allowing the embedded
flash memory to be reprogrammed under software control. ISP is performed without removing the
microcontroller from the system through the firmware and on-chip connectivity interface, such as
UART, USB, I
2
C, SPI, and CAN (depended on chip feature).
The NuMicro
®
M451 ISP provides the following functions for embedded flash memory.
Supports flash page erase function
Supports flash data program function