AT32UC3L064_11 ATMEL [ATMEL Corporation], AT32UC3L064_11 Datasheet - Page 87

• Manufacturer Part Number: AT32UC3L064_11
• Description: 32-bit Atmel AVR Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

10.2.7
10.2.8
32099HS–12/2011
GPIO
SPI
1. Clearing GPIO interrupt may fail
1. SPI data transfer hangs with CSR0.CSAAT==1 and MR.MODFDIS==0
2. Disabling SPI has no effect on the SR.TDRE bit
3. SPI disable does not work in SLAVE mode
4. SPI bad serial clock generation on 2nd chip_select when SCBR=1, CPOL=1, and
5. SPI mode fault detection enable causes incorrect behavior
Fix/Workaround
-When writing to the affected fields, the user must ensure a wait corresponding to 2 clock
cycles of both the WDT peripheral bus clock and the selected WDT clock source.
-When doing writes that changes the EN bit, the EN bit can be read back until it reflects the
written value.
Writing a one to the GPIO.IFRC register to clear an interrupt will be ignored if interrupt is
enabled for the corresponding port.
Fix/Workaround
Disable the interrupt, clear it by writing a one to GPIO.IFRC, then enable the interrupt.
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 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.
SPI disable does not work in SLAVE mode.
Fix/Workaround
Read the last received data, then perform a software reset by writing a one to the Software
Reset bit in the Control Register (CR.SWRST).
NCPHA=0
When multiple chip selects (CS) are in use, if one of the baudrates equal 1 while one
(CSRn.SCBR=1) of the others do not equal 1, and CSRn.CPOL=1 and CSRn.NCPHA=0,
then an additional pulse will be generated on SCK.
Fix/Workaround
When multiple CS are in use, if one of the baudrates equals 1, the others must also equal 1
if CSRn.CPOL=1 and CSRn.NCPHA=0.
When mode fault detection is enabled (MR.MODFDIS==0), the SPI module may not operate
properly.
Fix/Workaround
Always disable mode fault detection before using the SPI by writing a one to MR.MODFDIS.
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