ML51/ML54/ML56
Sep. 01, 2020
Page
584
of 719
Rev 2.00
ML
51
/ML
54
/ML
5
6 S
E
RI
E
S
TECHNI
CA
L
RE
F
E
R
E
NC
E
M
A
NU
A
L
ML51/M
L54
/M
L56
Series
Tec
hnical Reference
Manual
VRFCON
– Internal V
REF
Control (TA Protected)
Register
SFR Address
Reset Value
VRFCON
A9H,Page 1, TA protected
0000_0000 b
7
6
5
4
3
2
1
0
-
VRFSEL[2:0]
-
-
ENLOAD
ENVRF
-
R/W
-
-
R/W
R/W
Bit
Name
Description
[7]
-
Reserved
[6:4]
VRFSEL[2:0] Internal V
REF
Output Voltage Select
This field selects V
REF
output voltage.
000 = 1.538V , when V
DD
> 2.0V
001 = 2.048V , when V
DD
> 2.4V
010 = 2.560V , when V
DD
> 2.9V
011 = 3.072V , when V
DD
> 3.4V
100 = 4.096V , when V
DD
> 4.5V
101 = reserved
110 = reserved
111 = reserved
[3:2]
-
Reserved
[1]
ENLOAD
Internal V
REF
Pre-Load Enable
1 = Internal V
REF
Pre-load Enabled.
0 = Internal V
REF
Pre-load Disabled
[0]
ENVRF
Internal V
REF
Enable
1 = Internal V
REF
Enabled,
0 = Internal V
REF
Disabled
Note that a 1 uF has to add on V
REF
pin while internal V
REF
is enabled.