Datasheet

Table Of Contents
102
SAM9N12/SAM9CN11/SAM9CN12 [DATASHEET]
11063K–ATARM–05-Nov-13
12.2.5 SAM-BA Monitor
If no valid code has been found in NVM during the NVM bootloader sequence, the SAM-BA Monitor program is launched.
The SAM-BA Monitor principle is to:
Initialize DBGU and USB
Check if USB Device enumeration has occurred
Check if characters have been received on the DBGU
Once the communication interface is identified, the application runs in an infinite loop waiting for different commands as
listed in Table 12-5.
Figure 12-10. SAM-BA Monitor Diagram
Character(s) received
on DBGU ?
Run monitor
Wait for command
on the USB link
Run monitor
Wait for command
on the DBGU link
USB Enumeration
Successful ?
Ye s Ye s
No
No
Init DBGU and USB
No valid code in NVM