813
32099I–01/2012
AT32UC3L016/32/64
The CAT module does not terminate a QTouch burst when the detection voltage is
reached on the sense capacitor. This can cause the sense capacitor to be charged more
than necessary. Depending on the dielectric absorption characteristics of the capacitor, this
can lead to unstable measurements.
Fix/Workaround
Use the minimum possible value for the MAX field in the ATCFG1, TG0CFG1, and
TG1CFG1 registers.
4.
Autonomous CAT acquisition must be longer than AST source clock period
When using the AST to trigger CAT autonomous touch acquisition in sleep modes where the
CAT bus clock is turned off, the CAT will start several acquisitions if the period of the AST
source clock is larger than one CAT acquisition. One AST clock period after the AST trigger,
the CAT clock will automatically stop and the CAT acquisition can be stopped prematurely,
ruining the result.
Fix/Workaround
Always ensure that the ATCFG1.max field is set so that the duration of the autonomous
touch acquisition is greater than one clock period of the AST source clock.
35.1.13
aWire
1.
aWire CPU clock speed robustness
The aWire memory speed request command counter warps at clock speeds below approxi-
mately 5kHz.
Fix/Workaround
None.
2.
The aWire debug interface is reset after leaving Shutdown mode
If the aWire debug mode is used as debug interface and the program enters Shutdown
mode, the aWire interface will be reset when the part receives a wakeup either from the
WAKE_N pin or the AST.
Fix/Workaround
None.
35.1.14
CHIP
1.
Increased Power Consumption in VDDIO in sleep modes
If OSC0 is enabled in crystal mode when entering a sleep mode where the OSC0 is dis-
abled, this will lead to an increased power consumption in VDDIO.
Fix/Workaround
Solution 1: Disable OSC0 by writing a zero to the Oscillator Enable bit in the System Control
Interface (SCIF) Oscillator Control Register (SCIF.OSC0CTRL.OSCEN) before going to a
sleep mode where OSC0 is disabled.
Solution 2: Pull down or up XIN0 or XOUT0 with 1MOhm resistor.
35.1.15
I/O Pins
1.
PA17 has low ESD tolerance
PA17 only tolerates 500V ESD pulses (Human Body Model).
Fix/Workaround
Care must be taken during manufacturing and PCB design.