Figure 25-8. Other Switching Diagrams - Cirrus Logic EP93 Series User Manual

Analog Touch Screen Interface
EP93xx User's Guide
The register values for TSDirect can be derived from the switch positions shown in
8. A "1" in the register bit position indicates that the switch is made or closed. Therefore, the
TSDirect value for battery sampling should be set to 0x4000_0700, the TSDirect value for the
measuring the DAC feedback example should be set to 0x2000_0600, and the TSDirect
value for measuring a miscellaneous input example should be set to 0x0000_0601.
To use the miscellaneous measurement input, TSDIRECT should be set to 0x0000_0601 and
the input should be on Xp pin. By using this configuration, we can measure the FULL range,
25
from 0 to 3.3 V. Also, to use this function we need to configure 2 items in Syscon:
• Enable the Clock for the Touch Screen (KTDIV register in Syscon)
• Set the TIN bit in DeviceCfg in Syscon. This sets the Touch Screen controller to an
inactive state.
SW28
100K
100K
Not
Used
Not
Used
25-14
SAMPLE VBAT
TOUCH_PRESS
SW29
DAC
VDD
VBAT
SW22
SW8
SW23
SW30
SW19
SW11
SW20
SW13
A/D CONVERTER
SW21
SW0
IN
SW1
Not
SW2
Used
SW3
SW12
SW14
SW4
SW5
SW9
SW6
SW7
SW24
REF+
SW25
Not
SW26
Used
SW27
REF-
SW15
SW16
SW10
SW17
SW18

Figure 25-8. Other Switching Diagrams

Test DAC
TOUCH_PRESS
SW28
SW29
DAC
VDD
VBAT
100K
SW22
SW8
100K
SW23
SW30
SW19
SW11
SW20
SW13
A/D CONVERTER
SW21
SW0
IN
SW1
SW2
SW3
SW12
SW14
SW4
SW5
SW9
SW6
SW7
SW24
REF+
SW25
SW26
SW27
REF-
SW15
SW16
SW10
SW17
SW18
Copyright 2007 Cirrus Logic
Measure Other Misc Input
TOUCH_PRESS
SW28
SW29
VDD
100K
SW22
SW8
100K
SW23
SW30
SW19
SW11
SW20
SW13
A/D CONVERTER
SW21
SW0
IN
SW1
Not
SW2
Used
SW3
SW12
SW14
SW4
SW5
SW9
SW6
SW7
SW24
IN REF+
SW25
Not SW26
Used
SW27
REF-
SW15
SW16
SW10
SW17
SW18
Figure 25-
DAC
VBAT
DS785UM1