Lantronix DSTni-EX - Manual (Page 74)

66
RX Message Registers
A 4-message-deep FIFO stores the incoming messages. Status flags indicate how many
messages are stored. Additional flags determine from which acceptance filter the actual
message is coming from.
Figure 5-2. RX Message Routing
Rx
M
es
sage 1 MESSAGE
FILTERS
CAN Module
uP Bus
CAN BUS
Rx
M
es
sage 0
Rx
M
es
sage 3
Rx
M
es
sage 2
To read received messages:
1. Wait for rx_msg interrupt.
2. MessageReadLoop:
read message
acknowledge ‘ message read’ by writing a ‘ 1’ to MsgAv register
read MsgAv; reading a ‘ 1’ means a new message is available
IF MsgAv=1 THEN jump to MessageReadLoop
3. Acknowledge rx_msg interrupt by writing a ‘ 1’ to this register location.