at32ap7002 ATMEL Corporation, at32ap7002 Datasheet - Page 45

• Manufacturer Part Number: at32ap7002
• Description: Avr 32 32-bit Microcontroller
• Manufacturer: ATMEL Corporation

32054DS–AVR32–10/07
29. SSC - TF output is not correct
30. USART - TXD signal is floating in Modem and Hardware Handshaking mode
31. PWM - Impossible to update a period equal to 0 by using the CUPD register
32. WDT Clear is blocked after WDT Reset
TCMR.START = Receive Start,
TCMR.STTDLY = more than ZERO,
RCMR.START = Start on falling edge / Start on Rising edge / Start on any edge
RFMR.FSOS = None (input)
Fix/Workaround
None.
TF output is not correct (at least emitted one serial clock cycle later than expected) when:
TFMR.FSOS = Driven Low during data transfer/ Driven High during data transfer
TCMR.START = Receive start
RFMR.FSOS = None (Input)
RCMR.START = any on RF (edge/level)
Fix/Workaround
None.
The TXD signal is floating in Modem and Hardware Handshaking mode, but should be
pulled up.
Fix/Workaround
Enable pullup on this line in the PIO.
It is impossible to UPDATE a period equal to 0 by the using of the UPDATE register
(CUPD).
Fix/Workaround
To update a period equal to 0, write directly to the CPRD register.
A watchdog timer event will, after reset, block writes to the WDT_CLEAR register, prevent-
ing the program to clear the next Watchdog Timer Reset.
Fix/Workaround
If the RTC is not used a write to AVR32_RTC.ctrl.pclr = 1, instead of writing to
AVR32_WDT.clr, will reset the prescaler and thus prevent the watchdog event from happen-
ing. This will render the RTC useless, but prevents WDT reset because the RTC and WDT
share the same prescaler. Another sideeffect of this is that the watchdog timeout period will
be half the expected timeout period.
If the RTC is used one can disable the Watchdog Timer (WDT) after a WDT reset has
occured. This will prevent the WDT resetting the system. To make the WDT functional again
a hard reset (power on reset or RESET_N) must be applied. If you still want to use the WDT
a f t e r a W D T r e s e t a s m a l l c o d e c a n b e i n s e r te d a t t h e s ta r tu p c h e c k i n g t h e
AVR32_PM.rcause register for WDT reset and use a GPIO pin to reset the system. This
method requires that one of the GPIO pins are available and connected externally to the
RESET_N pin. After the GPIO pin has pulled down the reset line the GPIO will be reset and
leave the pin tristated with pullup.
AT32AP7002
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