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GD32L23x User Manual
599
switched on depend on the PULSE[2:0] bits in the SLCD_CFG register. The R
L
can be always
switched on according to setting the HDEN bit in the SLCD_CFG register.
Enhance mode:
The SLCD module integrates an optional voltage output driver, which can enter the enhanced
mode by enabling the VODEN bit of the SLCD_CTL register. Since the voltage output driver
is enabled, the voltage interference caused by the LCD capacitive load mounted on the bridge
can be reduced. Thus, a stable voltage can be obtained to enhance SLCD driving capacity.
In enhanced mode, the high value resistor bridge (R
HN
) will generate an intermediate voltage,
the HDEN bit or PULSE bit configuration will be ignored, and the low value resistor bridge
(R
LN
) will be automatically disabled, thereby reducing power consumption.
The VLCD power supply is not used for the voltage output driver. The voltage output driver
can only be configured when the SLCD controller is not activated.
25.3.7.
V
SLCD
voltage monitoring
The VSLCDEN bit in the ADC_CTL1 register is used to measure the V
SLCD
voltage. Since the
V
SLCD
voltage may be higher than V
DDA
, in order to ensure the normal operation of the ADC,
the internal V
SLCDrail1
analog voltage is connected to the ADC_IN19 input channel.
The V
SLCDrail1
value under different BIAS[1:0] biases is different, which is determined by the
internal analog circuit.
1.
BIAS[1:0]=00, V
SLCDrail1
=1/4V
SLCD
, V
SLCD
voltage monitoring function can be used, the
value obtained by ADC conversion is one-fourth of the V
SLCD
voltage.
2.
BIAS[1:0]=01, V
SLCDrail1
is an invalid value, and the V
SLCD
voltage monitoring function
cannot be used normally.
3.
BIAS[1:0]=10, V
SLCDrail1
=1/3V
SLCD
, V
SLCD
voltage monitoring function can be used, and
the value obtained by ADC conversion is one-third of the V
SLCD
voltage.
To prevent the battery power from being accidentally consumed, it is recommended to enable
VSLCDEN only when necessary to perform ADC conversion.