Figure 2-1. Adc Block Diagram - Sharp LH79524 User Manual

Analog-to-Digital Converter/Brownout Detector
AN0/UL/X+
AN1/UR/X-
AN2/IL/Y+
AN3/LR/Y-
AN4/WIPER
AN5
AN6/VBAT
AN7
AN8
AN9
A2DCLK DIGITA
EOSINTR
The ADC block can perform a sequence of measurements without intervention from the
ARM core. Examples include:
• Determining touch-screen biasing switch configuration.
• Ascertaining how much settling time is required before making a measurement.
• Determining the ADC input source and ADC reference source.
From 1 to 16 different measurements can be performed in a sequence. The number of
sequence steps is stored in the PC Register.
The biasing switch configuration, settling time, and ADC mux settings for each of the 1 to
16 measurements in the sequence are stored in an entry in the Control Bank. The mea-
surement sequence can be triggered by either software or a Pen Down Interrupt.
2-2
ANALOG
GPI
BIAS AND
MUX
CONTROL
VREF-
8
8
PenIRQ
GPEN
GPI
EOC penIRQ
CONTROL BANK STATE MACHINE
15
Start_acq A2DON HWR
oscen
A2DCLK DIGITAL
CLKSEL
CLOCK
A2DCLK ANALOG
GENERATOR
3
PWM
2

Figure 2-1. ADC Block Diagram

VLL
BrownOut_INTR
VREF
A2DCLK_ANALOG
+REF
11-TO-1
+IN
MUX
10b A/D OUT
-IN
START -REF
A2D0N
PWM
2
CBTAG
4
14
LWR
FwaterINTR
ADVANCED
PERIPHERAL
BUS (APB)
Version 1.0
LH79524/LH79525 User's Guide
AN8/VREF+EXT
AN0/UL/X+
4-TO-1
LL/Y+
MUX
VREF+
D[9:0]
10
VREF-EXT
AN1/UR/X-
4-TO-1
AN3/LR/Y-
MUX
VREF-
CBTAG
4
10-BIT
RESULT XX CBTAG
FIFO
FovmINTR
16
BANDGAPON
VREF+ EN
BGAP
VREF
VREF-
LH79525-52