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LH75400/01/10/11 (Preliminary) User’s Guide
Analog-to-Digital Converter/Brownout Detector
6/25/03
23-15
NOTE:
nIDLE refers to whether the state machine is in the Idle state:
0 = Control Bank State Machine is in the Idle state.
1 = Control Bank State Machine is in another state besides the Idle state.
A2DCLK ENABLE refers to whether the A2DCLK signal is enabled:
0 = Disables the A2DCLK to the analog circuitry. (The clock is always enabled to the digital circuitry.)
1 = Enables the A2DCLK to the analog circuitry.
BANDGAPON refers to whether Band Gap is turned on (Band Gap is required for the Brownout
Detector):
0 = Turns off the Band Gap, disabling the Brownout Detector.
1 = Turns on the Band Gap. This setting is required for the Brownout Detector to work.
A2DON refers to whether the analog circuitry is enabled for the ADC:
0 = Disables the analog circuitry for the ADC.
1 = Enables the analog circuitry for the ADC.
7:6 PWM
Touch Screen Controller Power Mode
00 =Turns off Power Mode and clock; sets the BROWNOUT field (bit [9]) of
the GS Register, indicating that a brownout is detected, even if
VDDA_ADC is at the correct voltage.
01 =Standby (wake on SSB or Pen Interrupt, convert, return); clears the
BROWNOUT field (bit [9]) of the GS Register, even if VDDA_ADC is at
the correct voltage.
10 =Run (always on); clears the BROWNOUT field (bit [9]) of the GS Register,
even if VDDA_ADC is at the correct voltage.
11 =Turns off Power Mode and clock; sets the BROWNOUT field (bit [9]) of
the GS Register, indicating that a brownout is detected, even if
VDDA_ADC is at the correct voltage.
The PWM field also affects the status of the A2DCLK signal, Band Gap, and
A2D signal (see Table 23-13).
5 REFEN
Reference Enable
Enables the internal reference buffer.
4 ///
Reserved
Read as zero.
3:0 NOC
Number of Conversions (NOC) in Sequence
Actual number of
conversions is NOC + 1. The number of conversions ranges from 1 to 16.
Table 23-13. Touch Screen Controller Power Modes
PWM BIT VALUES
nIDLE
A2DCLK ENABLE
BANDGAPON A2DON
00
0
0
0
0
00
1
0
0
0
01
0
0
1
0
01
1
1
1
1
10
0
0
1
1
10
1
1
1
1
11
0
0
0
0
11
1
0
0
0
Table 23-12. PC Register Definitions (Cont’d)
BIT
NAME
DESCRIPTION