Datasheet

32072SH–AVR32–10/2012

AT32UC3A3

SPI data transfer hangs with CSR0.CSAAT==1 and MR.MODFDIS==0

When CSR0.CSAAT==1 and mode fault detection is enabled (MR.MODFDIS==0), the SPI

module will not start a data transfer.

Fix/Workaround

Disable mode fault detection by writing a one to MR.MODFDIS.

Disabling SPI has no effect on the SR.TDRE bit

Disabling SPI has no effect on the SR.TDRE bit whereas the write data command is filtered

when SPI is disabled. Writing to TDR when SPI is disabled will not clear SR.TDRE. If SPI is

disabled during a PDCA transfer, the PDCA will continue to write data to TDR until its buffer

is empty, and this data will be lost.

Fix/Workaround

Disable the PDCA, add two NOPs, and disable the SPI. To continue the transfer, enable the

SPI and PDCA.

10.1.8 Power Manager

OSC32 not functionnal in Crystal Modes (OSC32CTRL.MODE=1 or

OSC32CTRL.MODE=2)

OSC32 clock output is not active even if the oscillation signal is present on XIN32/XOUT32

pins.

OSC32RDY bit may still set even if the CLK32 is not active.

External clock mode (OSC32CTRL.MODE=0) is not affected.

Fix/Workaround

None.

Clock sources will not be stopped in STATIC sleep mode if the difference between

CPU and PBx division factor is too high

If the division factor between the CPU/HSB and PBx frequencies is more than 4 when going

to a sleep mode where the system RC oscillator is turned off, then high speed clock sources

will not be turned off. This will result in a significantly higher power consumption during the

sleep mode.

Fix/Workaround

Before going to sleep modes where the system RC oscillator is stopped, make sure that the

factor between the CPU/HSB and PBx frequencies is less than or equal to 4.

10.1.9 PDCA

PCONTROL.CHxRES is non-functional

PCONTROL.CHxRES is non-functional. Counters are reset at power-on, and cannot be

reset by software.

Fix/Workaround

Software needs to keep history of performance counters.

Transfer error will stall a transmit peripheral handshake interface

If a transfer error is encountered on a channel transmitting to a peripheral, the peripheral

handshake of the active channel will stall and the PDCA will not do any more transfers on

the affected peripheral handshake interface.

Fix/Workaround

Disable and then enable the peripheral after the transfer error.