AT32UC3A0512_09 Datasheet, PDF (85/98 Pages) ATMEL Corporation – AVR 32 32-Bit Microcontroller

15.5.2 PWM
15.5.3 SSC
AT32UC3A
Fix/workaround
When multiple CS are in use, if one of the baudrate equals 1, the other must also equal 1 if
CPOL=1 and CPHA=0.
1. PWM counter restarts at 0x0001
The PWM counter restarts at 0x0001 and not 0x0000 as specified. Because of this the first
PWM period has one more clock cycle.
Fix/Workaround
- The first period is 0x0000, 0x0001, ..., period
- Consecutive periods are 0x0001, 0x0002, ..., period
2. PWM channel interrupt enabling triggers an interrupt
When enabling a PWM channel that is configured with center aligned period (CALG=1), an
interrupt is signalled.
Fix/Workaround
When using center aligned mode, enable the channel and read the status before channel
interrupt is enabled.
3. PWM update period to a 0 value does not work
It is impossible to update a period equal to 0 by the using the PWM update register
(PWM_CUPD).
Fix/Workaround
Do not update the PWM_CUPD register with a value equal to 0.
4. PWM channel status may be wrong if disabled before a period has elapsed
Before a PWM period has elapsed, the read channel status may be wrong. The CHIDx-bit
for a PWM channel in the PWM Enable Register will read '1' for one full PWM period even if
the channel was disabled before the period elapsed. It will then read '0' as expected.
Fix/Workaround
Reading the PWM channel status of a disabled channel is only correct after a PWM period
has elapsed.
1. SSC does not trigger RF when data is low
The SSC cannot transmit or receive data when CKS = CKDIV and CKO = none, in TCMR or
RCMR respectively.
Fix/Workaround
Set CKO to a value that is not "none" and bypass the output of the TK/RK pin with the PIO.
2. SSC Data is not sent unless clock is set as output
The SSC cannot transmit or receive data when CKS = CKDIV and CKO = none, in TCMR or
RCMR respectively.
Fix/Workaround
Set CKO to a value that is not "none" and bypass the output of the TK/RK pin with the PIO.
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32058HS–AVR32–03/09