at42qt1481 ATMEL Corporation, at42qt1481 Datasheet - Page 36

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

Table 4-5.
Hex
0x00
0x01
0x02
0x03
0x04
Name
Low Level Calibration
Enter Setups mode
Null command
Force reset
and Offset
Command Summary
CAL all
Description
Used to get data back in SPI mode
Enter Setups, stop sensing; followed
by block load of binary Setups of
length ‘nn’. Command must be
repeated twice consecutively without
any intervening command in 110 ms
to execute. Sensing autorestarts,
however, the QT1481 should be reset
after the block load to ensure all new
setups take effect.
Forces QT1481 to calibrate at all
three selected frequencies.
Command must be repeated twice
consecutively without any intervening
command in 110 ms to execute.
After completion, host should read
back the setups block, and then
upload the Setups block together with
the correct CRC.
Forces QT1481 to recalibrate all keys;
re-enters RUN mode afterwards
automatically; 0x03 must be repeated
twice consecutively without any
intervening command in 110 ms to
execute
Forces QT1481 to reset. Command
must be repeated twice consecutively
without any intervening command in
110 ms to execute
#/Cmd
2 + nn +
1
2
2
2
2
# Rtnd
1
2
1
1
1
Rtn Range
+ 0x00 (err)
0 – 0xFF
+ 0xFE
0xFE
0xFE
0xFD
0xFC
0xFB
OR
CRC
16
–
–
–
-
Description
Flushes pending data from QT1481; one required
to extract each response byte.
First 0xFE issued when ready to receive data,
second 0xFE issued when all loaded and burned;
else timeout.
If two commands not received in 110 ms, times
out and no response is issued. Part times out if
each byte not received within 110 ms of previous
byte.
If CRC failure, returns 0x00 instead of 0xFE
Data block length is ‘nn’ + 2 (CRC-16). LSL and
CRC should be sent low byte first.
Internal EEPROM updates regardless of CRC
health, but, if the CRC is bad, the EEPROM is
declared invalid and thus on reset the EEPROM
is restored from Flash backup, overwriting the
desired (but corrupt) new setups.
0xFD returned if command successfully received
and QT1481 is not processing a previous 0x02
command.
Returns 1’s complement of command to
acknowledge command once the calibration has
been initiated.
If two commands not received in 110 ms, times
out and no response is issued.
Returns 1’s complement of command to
acknowledge command prior to reset. If two
commands not received in 110 ms, times out and
no response is issued.
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