AT32UC3B0512-A2UES ATMEL [ATMEL Corporation], AT32UC3B0512-A2UES Datasheet - Page 82

• Manufacturer Part Number: AT32UC3B0512-A2UES
• Description: 32-bit AVR Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

12.2.3.4
12.2.3.5
12.2.3.6
12.2.3.7
12.2.3.8
SSC
USB
Cycle counter
ADC
USART
1. SSC does not trigger RF when data is low
1. USB No end of host reset signaled upon disconnection
2. USBFSM and UHADDR1/2/3 registers are not available
1. CPU Cycle Counter does not reset the COUNT system register on COMPARE match.
1. ADC possible miss on DRDY when disabling a channel
2. ADC OVRE flag sometimes not reset on Status Register read
3. Sleep Mode activation needs addtionnal A to D conversion
1. USART Manchester Encoder Not Working
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 GPIO.
In host mode, in case of an unexpected device disconnection whereas a usb reset is being
sent by the usb controller, the UHCON.RESET bit may not been cleared by the hardware at
the end of the reset.
Fix/Workaround
A software workaround consists in testing (by polling or interrupt) the disconnection
(UHINT.DDISCI == 1) while waiting for the end of reset (UHCON.RESET == 0) to avoid
being stuck.
Do not use USBFSM register.
Fix/Workaround
Do not use USBFSM register and use HCON[6:0] field instead for all the pipes.
The device revision B does not reset the COUNT system register on COMPARE match. In
this revision, the COUNT register is clocked by the CPU clock, so when the CPU clock
stops, so does incrementing of COUNT.
Fix/Workaround
None.
The ADC does not work properly when more than one channel is enabled.
Fix/Workaround
Do not use the ADC with more than one channel enabled at a time.
The OVRE flag does not clear properly if read simultaneously to an end of conversion.
Fix/Workaround
None.
If the ADC sleep mode is activated when the ADC is idle the ADC will not enter sleep mode
before after the next AD conversion.
Fix/Workaround
Activate the sleep mode in the mode register and then perform an AD conversion.