Datasheet

966
SAM9X35 [DATASHEET]
11055E–ATARM–10-Mar-2014
42.8.18 ADC Touchscreen Mode Register
Name: ADC_TSMR
Address: 0xF804C0B0
Access: Read-write
This register can only be written if the WPEN bit is cleared in “ADC Write Protect Mode Register” on page 972.
• TSMODE: Touchscreen Mode
When TSMOD equals 01 or 10 (i.e. 4-wire mode), channel 0, 1, 2 and 3 must not be used for classic ADC conversions. When
TSMOD equals 11 (i.e. 5-wire mode), channel 0, 1, 2, 3, and 4 must not be used.
• TSAV: Touchscreen Average
• TSFREQ: Touchscreen Frequency
Defines the Touchscreen Frequency compared to the Trigger Frequency.
TSFREQ must be greater or equal to TSAV.
The Touchscreen Frequency is:
Touchscreen Frequency = Trigger Frequency / 2
TSFREQ
• TSSCTIM: Touchscreen Switches Closure Time
Defines closure time of analog switches necessary to establish the measurement conditions.
The Closure Time is:
Switch Closure Time = (TSSCTIM * 4) ADCClock periods.
31 30 29 28 27 26 25 24
PENDBC – – – PENDET
23 22 21 20 19 18 17 16
– NOTSDMA – – TSSCTIM
15 14 13 12 11 10 9 8
–––– TSFREQ
76543210
–– TSAV –– TSMODE
Value Name Description
0NONENo Touchscreen
1 4_WIRE_NO_PM 4-wire Touchscreen without pressure measurement
24_WIRE4-wire Touchscreen with pressure measurement
35_WIRE5-wire Touchscreen
Value Name Description
0NO_FILTERNo Filtering. Only one ADC conversion per measure
1AVG2CONVAverages 2 ADC conversions
2AVG4CONVAverages 4 ADC conversions
3AVG8CONVAverages 8 ADC conversions