WM9713L_06 WOLFSON [Wolfson Microelectronics plc], WM9713L_06 Datasheet - Page 62

• Manufacturer Part Number: WM9713L_06
• Description: AC 97 Audio + Touchpanel CODEC
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

WM9713L
CONTROLLING THE TOUCHPANEL DIGITISER
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All touchpanel functions are accessed and controlled through the AC-Link interface.
PHYSICAL CHARACTERISTICS
The physical characteristics of the touchpanel interface are controlled through register 78h, as shown
below.
Table 46 Touchpanel Digitiser Control (Physical Characteristics)
POWER MANAGEMENT
To save power, the touchpanel digitiser and the pen-down detector can be independently disabled
when they are not used. The power consumption of the pen-down detector is normally negligible,
except when the pen is down.
The pen ADC is powered-down using PADCPD, register 3Ch bit 15.
The state of the digitiser and pen down detector is controlled by the following bits.
Table 47 Touchpanel Digitiser Control (Power Management)
78h
3Ch
78h
REGISTER
REGISTER
ADDRESS
ADDRESS
12
8
0:5
15
15:14
13
BIT
BIT
45W
PIL
RPU
LABEL
PADCPD
PRP
RPR
LABEL
0 (4-wire)
0 (200 A)
000001
(64k )
DEFAULT
1 = off
00
0
DEFAULT
Touchpanel Type Selection
0: 4-wire
1: 5-wire
Current used for pressure measurement
0: I
1: I
Internal Pull-up resistor for Pen Detection
111111: 64k /63 = 1.02k
111110: 64K /62 = 1.03K
… (pull-up = 64k
000010: 64K /2 = 32K
000001: 64k /1 = 64k
000000: RESERVED (do not use this setting)
P
P
Pen ADC power down
Pen ADC/AUX ADC enable
00 – Pen digitiser off, pen detect off, no
wake-up on pen down (default)
01 – Pen digitiser powered off, pen detect
enabled, touchpanel digitiser wakes up
(changes to state 11) on pen-down
10 – Pen digitiser off, pen detect enabled,
no wake-up on pen down
11 – Pen digitiser and pen detect enabled
Wake-up on pen-down mode
0: Wake-up the AC-Link only (hold
SDATAIN high until controller sends warm
reset or cold reset)
1: Wake-up the WM9713L without waiting
for a reset signal from the controller
= 200 A
= 400 A
DESCRIPTION
DESCRIPTION
/ binary value of RPU)
(most sensitive)
PP Rev 3.0 June 2006
(least sensitive)
Pre-Production
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