Freescale Semiconductor MPC5200B - Manual (Page 715)

MPC5200B Users Guide, Rev. 1
20-36 Freescale Semiconductor
Functional Description
Figure 20-14. Basic BDLC Receive Flowchart
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.
Enter BDLC module Receive
Is DLCBSVR
No
Store received byte
(in case of LOA)
Is this message
Yes
No
Is this an IFR
Yes
No
Is DLCBSVR = $04?
No
Yes
(EOF)
reception?
of any interest?
Is this a transmit
Yes
No
reflection?
Yes
A
B
Jump to Receive IFR
Handling Routine
Once BDLC module Detects
Go to BDLC module
BREAK/Error Handling
reception is complete
Yes
No
Is DLCBSVR
Jump to Transmit IFR
Handling Routine
Exit BDLC module Receive
Routine
B
Routine
(Error Detected)
(RDRF)
Read byte in DLCBDR
Filter received byte
Set IMSG bit in DLCBCR1 Store received byte
Is an IFR to
Yes
No
be transmitted?
B
A
Routine
EOF, message
= $1C/$18?
= $0C?