350
4317I–AVR–01/08
AT90PWM2/3/2B/3B
32. Errata
32.1
AT90PWM2&3 Rev. A (Mask Revision)
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PGM: PSCxRB Fuse
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PSC: Prescaler
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PSC: PAOCnA and PAOCnB Register Bits (Asynchronous output control)
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PSC: PEVxA/B Flag Bits
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PSC: Output Polarity in Centered Mode
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PSC: Output Activity
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VREF
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DALI
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DAC: Register Update
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DAC: Output spikes
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DAC driver: Output Voltage linearity
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ADC: Conversion accuracy
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Analog comparator: Offset value
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Analog comparator: Output signal
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PSC: Autolock modes
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DALI: 17th bit detection
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PSC: One ramp mode with PSC input mode 8
1.
PGM: PSCnRB Fuse
The use of PSCnRB fuse can make the parallel ISP fail.
Workaround:
When PSCnRB fuses are used, use the serial programming mode to load a new program
version.
2.
PSC: Prescaler
The use of PSC's prescaler have the following effects :
It blocks the sample of PSC inputs until the two first cycles following the set of PSC run bit.
A fault is not properly transferred to other (slave) PSC.
Workaround:
Clear the prescaler PPREx bit when stopping the PSC (prun = 0), and set them to appropri-
ate value when starting the PSC (prun = 1), these bits are in the same PCTL register
Do not use the prescaler when a fault on one PSC should affect other PSC’s
3.
PSC: PAOCnA and PAOCnB Register Bits (Asynchronous output control)
These register bits are malfunctioning.
Workaround:
Do not use this feature.
4.
PSC: PEVnA/B flag bits
These flags are set when a fault arises, but can also be set again during the fault itself.
Workaround:
Don't clear these flags before the fault disappears.