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26.2.2 VREF Status and Control Register (VREF_SC)
This register contains the control bits used to enable the internal voltage reference and to
select the buffer mode to be used.
Address: 4007_4000h base + 1h offset = 4007_4001h
Bit
7
6
5
4
3
2
1
0
Read
Write
Reset
0
0
0
0
0
0
0
0
VREF_SC field descriptions
Field
Description
7
VREFEN
Internal Voltage Reference enable
This bit is used to enable the bandgap reference within the Voltage Reference module.
NOTE: After the VREF is enabled, turning off the clock to the VREF module via the corresponding clock
gate register will not disable the VREF. VREF must be disabled via this VREFEN bit.
0
The module is disabled.
1
The module is enabled.
6
REGEN
Regulator enable
This bit is used to enable the internal 1.75 V regulator to produce a constant internal voltage supply in
order to reduce the sensitivity to external supply noise and variation. If it is desired to keep the regulator
enabled in very low power modes, refer to the Chip Configuration details for a description on how this can
be achieved.
This bit should be written to 1 to achieve the performance stated in the data sheet.
0
Internal 1.75 V regulator is disabled.
1
Internal 1.75 V regulator is enabled.
5
ICOMPEN
Second order curvature compensation enable
This bit should be written to 1 to achieve the performance stated in the data sheet.
0
Disabled
1
Enabled
4
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
3
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
2
VREFST
Internal Voltage Reference stable
This bit indicates that the bandgap reference within the Voltage Reference module has completed its
startup and stabilization.
NOTE: This bit is valid only when the chop oscillator is not being used.
Table continues on the next page...
Chapter 26 Voltage Reference (VREFV1)
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
Freescale Semiconductor, Inc.
427