SAM7X256_14 Datasheet, PDF (620/662 Pages) ATMEL Corporation – ARM-based Flash MCU

41.4.2 Controller Area Network (CAN)
41.4.2.1 CAN: Low Power Mode and Error Frame
If the Low Power Mode is activated while the CAN is generating an error frame, this error frame may be shortened.
Problem Fix/Workaround
None
41.4.2.2 CAN: Low Power Mode and Pending Transmit Messages
No pending transmit messages may be sent once the CAN Controller enters Low-power Mode.
Problem Fix/Workaround
Check that all messages have been sent by reading the related Flags before entering Low-power Mode.
41.4.3 Embedded Flash Controller (EFC)
41.4.3.1 EFC: Embedded Flash Access Time
The embedded Flash maximum access time is 25 MHz (instead of 30 MHz at zero Wait State (FWS = 0). The maximum
operating frequency with one Wait State (FWS = 1) is still 55 MHz.
Problem Fix/Workaround
Set one wait state (FWS = 1) if the frequency is above 25 MHz.
41.4.4 Ethernet MAC (EMAC)
41.4.4.1 EMAC: Possible Event Loss when Reading EMAC_ISR
If an event occurs within the same clock cycle in which the EMAC_ISR is read, the corresponding bit might be cleared
even though it has not been read at 1. This might lead to the loss of this event.
Problem Fix/Workaround
Each time the software reads EMAC_ISR, it has to check the contents of the Transmit Status Register (EMAC_TSR), the
Receive Status Register (EMAC_RSR) and the Network Status Register (EMAC_NSR), as the possible lost event is still
notified in one of these registers.
41.4.4.2 EMAC: Possible Event Loss when Reading the Statistics Register Block
If an event occurs within the same clock cycle during which a statistics register is read, the corresponding counter might
lose this event. This might lead to the loss of the incrementation of one for this counter.
Problem Fix/Workaround
None
41.4.5 Peripheral Input/Output (PIO)
41.4.5.1 PIO: Leakage on PB27 - PB30
When PB27, PB28, PB29 or PB30 (the I/O lines multiplexed with the analog inputs) are set as digital inputs with pull-up
disabled, the leakage can be 25 µA in worst case and 90 nA in typical case per I/O when the I/O is set externally at low
level.
Problem Fix/Workaround
Set the I/O to VDDIO by internal or external pull-up.
SAM7X Series [DATASHEET]
6120K–ATARM–11-Feb-14
620