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SAMA5D3x-EK User Guide [USER GUIDE]
11180B–ATARM–29-Oct-13
5.2.15.2
CS_BOOT Button
The CS_BOOT can be used to prevent the system from booting out of external memories (NANDFlash, SPI Flash). The
purpose is mainly to execute the SAM-BA part of the ROM code.
Two methods can be used:
1.
Press the CS_BOOT and power-cycle the board.
2.
Press the CS_BOOT and then press the NRST button.
Figure 5-19.
Pushbutton
5.2.16 Analog Reference
The 3V voltage reference is based on an LM4040 (Precision Micropower Shunt Voltage Reference).
This ADVREF level can be set as 3V or 3.3V via the jumper JP14.
Figure 5-20.
Analog Reference
3V3
NRST
3,10,14
WAKE UP 3
VBAT
PE27
3,9,13
CS_BOOT_DISABLE
3
WAKE UP
NRST
PUSH BUTTON
PB_USER1
PB_USER1
CS_BOOT
PB1
PB1
PB2
PB2
R142
1.5k
R142
1.5k
PB3
PB3
R141
100k
R141
100k
PB4
PB4
R46
0R
R46
0R
VDDANA
5V
ADVREF
3V
ANALOG Reference 3V
JP14
JP14
1
2
3
C112
100n
C112
100n
D6
LM4040BIM3-3.0+T
D6
LM4040BIM3-3.0+T
R143
1.5k
R143
1.5k
C113
2.2u
C113
2.2u