Transmitting An In-Frame Response (Ifr); Basic Bdlc Receive Flowchart - Freescale Semiconductor MPC5200B User Manual

Functional Description
Jump to Receive IFR
Handling Routine
Once BDLC module Detects
EOF, message
reception is complete
20.8.6

Transmitting An In-Frame Response (IFR)

The BDLC module can be used to transmit all four types of In-Frame Response (IFR) which are defined in SAE J1850. A very brief definition
of each IFR type is given below. For a more detailed description of each, refer the SAE J1850 document.
The explanation regarding IFR support by the BDLC module which assumes the user is familiar with the use of IFRs as defined in SAE J1850,
and understands the message header bit encoding and normalization bit formats which are used with the different types of IFRs. For more
information on this, refer to the SAE J1850 document.
20-36
Enter BDLC module Receive
Routine
Is DLCBSVR
Yes
= $1C/$18?
(Error Detected)
No
Is DLCBSVR
Yes
= $0C?
(RDRF)
No
Yes
Is this an IFR
reception?
No
B
Yes
Is DLCBSVR = $04?
(EOF)
No
A
Exit BDLC module Receive
Routine
Jump to Transmit IFR
Handling Routine
Figure 20-14. Basic BDLC Receive Flowchart
MPC5200B Users Guide, Rev. 1
Go to BDLC module
BREAK/Error Handling
Routine
Read byte in DLCBDR
No
Is this a transmit
reflection?
Yes
Store received byte
(in case of LOA)
Store received byte
Yes
Is an IFR to
be transmitted?
No
B
B
Filter received byte
Yes
Is this message
of any interest?
No
Set IMSG bit in DLCBCR1
A
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