at42qt2100 ATMEL Corporation, at42qt2100 Datasheet - Page 22

• Manufacturer Part Number: at42qt2100
• Description: Qtouch Touch Sensor Ic
• Manufacturer: ATMEL Corporation

22
AT42QT2100
Table 5-3.
Table 5-4.
Byte 2
Table 5-5.
Cal Key Num Bits
LPB – Sets the LP mode “following burst” option. See
In modes 101 (Sync) and 110 (Sleep), there will always be a burst following SS raising
high, regardless of the LPB Setting. See
DI - Set the “Detect Integrator” noise filter function.
MOD (Recal Time) – Sets the “Maximum On-duration” for all keys and slider/wheel.
Controls the time from the start of a detection to automatic recalibration of all channels.
See
Note: in “Sleep” mode, all device timing is dependent on the regularity of SPI
Cal Key Num – key to be recalibrated when CalK = 1 (see
LP Mode Bits
MOD Bits
LPB = 0: If the host communicates with the device, or there is an SS pulse during any
LP mode (modes 001 to 100), there will be no following burst. The only bursts that will
take place are those that occur as naturally defined by the LP mode noted above.
LPB = 1: If the host communicates with the device, or there is an SS pulse during any
LP mode (modes 001 to 100), there will be an additional burst following SS raising high
(default).
DI = 0: Two detections required to confirm a touch (faster but less noise immune).
DI = 1: Six detections required to confirm a touch (slower but more noise immune;
appropriate for most applications) (default).
Table 5-4
101
110
111
000
001
010
00
01
10
11
communications. See
Sleep/Low Power Modes
Maximum On-duration in Free Run Mode
Key Recalibration
for allowed MOD times.
Operating Mode
Sync mode:
The QT2100 performs an acquisition burst when triggered by a rising edge on
SS and ‘heartbeat’ bursts at the same interval as LP Mode 4
Sleep:
The QT2100 performs an acquisition and processing cycle only when triggered
by a rising edge on SS, whether a low pulse or a communication exchange.
Reserved
Maximum On-duration
10s (default)
20s
60s
Infinite MOD – timeout disabled
Key
Recalibrate all keys (excluding slider/wheel)
Recalibrate Key 1
Recalibrate Key 2
Section 4.4.4 on page 18
Table 5-3
for a description of the Mode settings.
Figure 4-2 on page
for more information.
Table
5-5).
18.
9554CX–AT42–11/11