at42qt1481 ATMEL Corporation, at42qt1481 Datasheet - Page 29

• Manufacturer Part Number: at42qt1481
• Description: 48-key Qmatrix Ic
• Manufacturer: ATMEL Corporation

9621B–AT42–06/11
Device Status: This byte is a collection of general status bits, see
Table 4-1.
Bit 6: Set if calibration failed on any enabled key.
Bit 5: Set if an FMEA error was detected during operation. This flag will be set during calibration
after reset, and should be ignored until calibration has completed. See
Bit 4: Set if a mismatch occurs with the setups CRC. If this happens, it is recommended that the
QT1481 be reset, which forces the setups to be recovered from internal Flash. If a reset does
not cure the problem, the setups block should be reloaded (see
the QT1481 reset again. The time required to recompute the Setups CRC and report an error is
a maximum of 1150 ms.
Bit 3: Set if there was a mains sync error, for example there was no Sync signal detected within
the allotted 100 ms amount of time. See
necessarily fatal to operation, however the QT1481 operates very slowly and may suffer from
noise problems if the sync feature is required for noise reasons.
Bit 2: Reports that an enabled key has a low signal reference value, lower than the user-settable
LSL value (see
Bit 1: Set if any key is in the process of calibrating.
Touch Overview: This byte gives an initial indication of the number of keys touched as well as
the number of the first touched key, as follows:
Table 4-2.
Bits 7 – 6: A 2-bit unsigned value indicating the number of touched keys. A value of three
indicates that three or more keys are touched.
Bit
7 – 6
5 – 0
Bit
7
6
5
4
3
2
1
0
Device Status Bits
Key Touch Information
Section 5.18 on page
Description
Reserved
1 = Calibration has failed on an enabled key
1 = FMEA failure detected
1 = Setups CRC mismatch
1 = Mains sync error
1 = LSL failure
1 = Any key in calibration
Reserved
Description
0 = No touched keys
1 = 1 key in detect
2 = 2 keys in detect
3 = 3 or more keys in detect
Number of 1st key declaring detect (0 – 47)
48).
Section 5.14 on page
Section 5.31 on page
Table 4-1 on page
46. This condition is not
Section 2.17 on page
AT42QT1481
29.
53) and
16.
29