Atmel Xplained Pro Evaluation Kit ATSAM4E-XPRO ATSAM4E-XPRO Data Sheet
Product codes
ATSAM4E-XPRO
659
SAM4E [DATASHEET]
Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14
It is also possible to configure a mailbox in Consumer Mode. In this mode, after each transfer request, a remote
frame is automatically sent. The first answer received is stored in the corresponding mailbox data registers.
frame is automatically sent. The first answer received is stored in the corresponding mailbox data registers.
Several mailboxes can be chained to receive a buffer. They must be configured with the same ID in Receive Mode,
except for the last one, which can be configured in Receive with Overwrite Mode. The last mailbox can be used to
detect a buffer overflow.
except for the last one, which can be configured in Receive with Overwrite Mode. The last mailbox can be used to
detect a buffer overflow.
33.7.2.3 Transmit Mailbox
When transmitting a message, the message length and data are written to the transmit mailbox with the correct
identifier. For each transmit mailbox, a priority is assigned. The controller automatically sends the message with
the highest priority first (set with the field PRIOR in CAN_MMRx).
identifier. For each transmit mailbox, a priority is assigned. The controller automatically sends the message with
the highest priority first (set with the field PRIOR in CAN_MMRx).
It is also possible to configure a mailbox in Producer Mode. In this mode, when a remote frame is received, the
mailbox data are sent automatically. By enabling this mode, a producer can be done using only one mailbox
instead of two: one to detect the remote frame and one to send the answer.
mailbox data are sent automatically. By enabling this mode, a producer can be done using only one mailbox
instead of two: one to detect the remote frame and one to send the answer.
Table 33-4.
Receive Mailbox Objects
Object Type
Description
Receive
The first message received is stored in mailbox data registers. Data remain available until the
next transfer request.
next transfer request.
Receive with overwrite
The last message received is stored in mailbox data register. The next message always
overwrites the previous one. The application has to check whether a new message has not
overwritten the current one while reading the data registers.
overwrites the previous one. The application has to check whether a new message has not
overwritten the current one while reading the data registers.
Consumer
A remote frame is sent by the mailbox. The answer received is stored in mailbox data register.
This extends Receive mailbox features. Data remain available until the next transfer request.
This extends Receive mailbox features. Data remain available until the next transfer request.
Table 33-5.
Transmit Mailbox Objects
Object Type
Description
Transmit
The message stored in the mailbox data registers will try to win the bus arbitration immediately
or later according to or not the Time Management Unit configuration (see
or later according to or not the Time Management Unit configuration (see
The application is notified that the message has been sent or aborted.
Producer
The message prepared in the mailbox data registers will be sent after receiving the next remote
frame. This extends transmit mailbox features.
frame. This extends transmit mailbox features.