
127
42073A-MCU Wireless-02/13
ATmega2564/1284/644RFR2
9.12.23 VREG_CTRL – Voltage Regulator Control and Status Register
Bit
7
6
5
4
NA ($150)
AVREG_EXT
AVDD_OK
AVREG_TRIM1
AVREG_TRIM0
VREG_CTRL
Read/Write
RW
R
RW
Initial Value
0
Bit
3
2
1
0
NA ($150)
DVREG_EXT
DVDD_OK
DVREG_TRIM1
DVREG_TRIM0
VREG_CTRL
Read/Write
RW
R
RW
Initial Value
0
This register controls the use of the voltage regulators and indicates their status.
Bit 7 – AVREG_EXT - Use External AVDD Regulator
This bit is reserved for IC test and should not be modified by the application firmware. If
set, this register bit disables the internal analog voltage regulator to apply an external
regulated 1.8V supply for the analog building blocks.
Table 9-56 AVREG_EXT Register Bits
Register Bits
Value
Description
AVREG_EXT
0
Internal AVDD voltage regulator for the
analog section is enabled.
1
Internal AVDD voltage regulator is disabled.
Bit 6 – AVDD_OK - AVDD Supply Voltage Valid
This register bit indicates if the internal 1.8V regulated voltage supply AVDD has
settled. The bit is set to logic high if AVREG_EXT = 1.
Table 9-57 AVDD_OK Register Bits
Register Bits
Value
Description
AVDD_OK
0
Analog voltage regulator disabled or supply
voltage not stable
1
Analog supply voltage has settled
Bit 5:4 – AVREG_TRIM1:0 - Adjust AVDD Supply Voltage
These bits are reserved for internal use. They allow adjusting the value of the analog
supply voltage (AVDD).
Table 9-58 AVREG_TRIM Register Bits
Register Bits
Value
Description
AVREG_TRIM1:0
0
1.80V
1
1.75V
2
1.84V
3
1.88V
Bit 3 – DVREG_EXT - Use External DVDD Regulator
This bit may be set in the Register, but is deactivated in the design. The DVREG_EXT
functionality to deactivate the digital voltage regulator is no implemented anymore
Table 9-59 DVREG_EXT Register Bits
Register Bits
Value
Description
DVREG_EXT
0
Internal DVDD voltage regulator for the
digital section is enabled.