SAM3X8E Atmel Corporation, SAM3X8E Datasheet - Page 1229

• Manufacturer Part Number: SAM3X8E
• Manufacturer: Atmel Corporation

Figure 40-17. Producer Handling
11057A–ATARM–17-Feb-12
11057A–ATARM–17-Feb-12
(CAN_MSRx)
(CAN_MCRx)
(CAN_MSRx)
CAN_MDHx)
(CAN_MDLx
Producer Configuration
Consumer Configuration
CAN BUS
MRDY
MTCR
MMI
Message 1
Remote Frame
Mailboxes can be configured in Producer or Consumer Mode. A lonely mailbox can handle the
remote frame and the answer. With
producers/consumers.
A mailbox is in Producer Mode once the MOT field in the CAN_MMRx register has been config-
ured. Message ID and Message Acceptance masks must be set before Receive Mode is
enabled.
After Producer Mode is enabled, the MRDY flag in the CAN_MSR register is automatically set
until the first transfer command. The software application prepares data to be sent by writing to
the CAN_MDHx and the CAN_MDLx registers, then by setting the MTCR bit in the CAN_MCRx
register. Data is sent after the reception of a remote frame as soon as it wins the bus arbitration.
The MRDY flag remains at zero as long as the message has not been sent or aborted. No
access to the mailbox data register can be done while MRDY flag is cleared. An interrupt is
pending for the mailbox while the MRDY flag is set. This interrupt can be masked according to
the mailbox flag in the CAN_IMR global register.
If a remote frame is received while no data are ready to be sent (signal MRDY set in the
CAN_MSRx register), then the MMI signal is set in the CAN_MSRx register. This bit is cleared
by reading the CAN_MSRx register.
The MRTR field in the CAN_MSRx register has no meaning. This field is used only when using
Receive and Receive with Overwrite modes.
After a remote frame has been received, the mailbox functions like a transmit mailbox. The mes-
sage with the highest priority is sent first. The transmitted message may be aborted by setting
the MACR bit in the CAN_MCR register. Please refer to the section
page
A mailbox is in Consumer Mode once the MOT field in the CAN_MMRx register has been config-
ured. Message ID and Message Acceptance masks must be set before Receive Mode is
enabled.
After Consumer Mode is enabled, the MRDY flag in the CAN_MSR register is automatically
cleared until the first transfer request command. The software application sends a remote frame
by setting the MTCR bit in the CAN_MCRx register or the MBx bit in the global CAN_TCR regis-
1227.
Message 1
Reading CAN_MSRx
Remote Frame
Message 2
8
mailboxes, the CAN controller can handle
Remote Frame
“Transmission Handling” on
SAM3X/A
SAM3X/A
Message 2
8
independent
1229
1229