SAM7X256_14 Datasheet, PDF (636/662 Pages) ATMEL Corporation – ARM-based Flash MCU

41.6.2 Controller Area Network (CAN)
41.6.2.1 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
41.6.2.2 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.
41.6.3 Embedded Flash Controller (EFC)
41.6.3.1 EFC: Embedded Flash Access Time
The embedded Flash maximum access time (FWS) is shown in Table 41-2:
Table 41-2. Embedded Flash Access Time
Flash Wait State (FWS)
Read Operations
Maximum Operating Frequency (MHz)
0
1 cycle
16
1
2 cycles
32
2
3 cycels
48
3
4 cycles
55
Problem Fix/Workaround
Set the number of wait states (FWS) depending on frequency as specified in Table 41-2.
41.6.4 Ethernet MAC (EMAC)
41.6.4.1 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.
41.6.4.2 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
SAM7X Series [DATASHEET]
6120K–ATARM–11-Feb-14
636