Rainbow Electronics AT91CAP9S250A - Manual (Page 701)

701
6264A–CAP–21-May-07
AT91CAP9S500A/AT91CAP9S250A
If several mailboxes are chained to receive a buffer split into several messages, all mailboxes
except the last one (with the highest number) must be configured in Receive Mode. The first
message received is handled by the first mailbox, the second one is refused by the first mail-
box and accepted by the second mailbox, the last message is accepted by the last mailbox
and refused by previous ones (see
Figure 39-13 ).
Figure 39-13. Chaining Three Mailboxes to Receive a Buffer Split into Three Messages
If the number of mailboxes is not sufficient (the MMI flag of the last mailbox raises), the user
must read each data received on the last mailbox in order to retrieve all the messages of the
buffer split (see
Figure 39-14 ).
MMI
(CAN_MSRx)
MRDY
(CAN_MSRx)
CAN BUS Message s1
Reading CAN_MSRx, CAN_MSRy and CAN_MSRz
Writing MBx MBy MBz in CAN_TCR
Reading CAN_MDH & CAN_MDL for mailboxes x, y and z
MMI
(CAN_MSRy)
MRDY
(CAN_MSRy)
MMI
(CAN_MSRz)
MRDY
(CAN_MSRz)
Message s2 Message s3
Buffer split in 3 messages