AT32UC3C1512C Automotive Atmel Corporation, AT32UC3C1512C Automotive Datasheet - Page 1297

• Manufacturer Part Number: AT32UC3C1512C Automotive
• Manufacturer: Atmel Corporation

43.2.5
43.2.6
9166C–AVR-08/11
SCIF
SPI
1
2
1
2
3
If the CPU is put to a sleep mode (except Idle and Frozen) directly after a TWI Start condi-
tion, the CPU may not wake upon a TWIS address match. The request is NACKed.
Fix/Workaround
When using the TWI address match to wake the device from sleep, do not switch to sleep
modes deeper than Frozen. Another solution is to enable asynchronous EIC wake on the
TWIS clock (TWCK) or TWIS data (TWD) pins, in order to wake the system up on bus
events.
PLLCOUNT value larger than zero can cause PLLEN glitch
Initializing the PLLCOUNT with a value greater than zero creates a glitch on the PLLEN sig-
nal during asynchronous wake up.
Fix/Workaround
The lock-masking mechanism for the PLL should not be used.
The PLLCOUNT field of the PLL Control Register should always be written to zero.
PLL lock might not clear after disable
Under certain circumstances, the lock signal from the Phase Locked Loop (PLL) oscillator
may not go back to zero after the PLL oscillator has been disabled. This can cause the prop-
agation of clock signals with the wrong frequency to parts of the system that use the PLL
clock.
Fix/Workaround
PLL must be turned off before entering STOP, DEEPSTOP or STATIC sleep modes. If PLL
has been turned off, a delay of 30us must be observed after the PLL has been enabled
again before the SCIF.PLL0LOCK bit can be used as a valid indication that the PLL is
locked.
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.
SPI disable does not work in SLAVE mode
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).
AT32UC3C
1297