AT91SAM7X512_1 Datasheet, PDF (644/687 Pages) ATMEL Corporation – AT91 ARM Thumb-based Microcontrollers

41.2.2 Controller Area Network (CAN)
41.2.2.1
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
41.2.2.2
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.
41.2.3 Ethernet MAC (EMAC)
41.2.3.1
EMAC: RMII Mode
RMII mode is not functional.
Problem Fix/Workaround
None
41.2.3.2
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 correspond-
ing 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.
41.2.3.3
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 cor-
responding counter might lose this event. This might lead to the loss of the incrementation of
one for this counter.
Problem Fix/Workaround
None
41.2.4 Peripheral Input/Output (PIO)
41.2.4.1
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.
644 AT91SAM7X512/256/128 Preliminary
6120H–ATARM–17-Feb-09