CDC3205G-C Micronas, CDC3205G-C Datasheet - Page 177

• Manufacturer Part Number: CDC3205G-C
• Description: Automotive Controller Family The Device is a Microcontroller For Use in Automotive Applications.the On-chip Cpu is an Arm Processor ARM7TDMI with 32-bit Data And Address Bus, Which Supports Thumb format Instructions.
• Manufacturer: Micronas

PRELIMINARY DATA SHEET
27.2.4. Communication Area (CA)
The CA is located in the CAN-RAM. It consists of com.
objects each of which is 16 bytes long. The CA begins at
address 0 of the CAN-RAM with the first byte of a CO. It ends
with the first byte of a CO which contains ones in its 3 MSBs
(communication mode = 7 = EoCA). The following bytes can
be used by the application. If the CAN-RAM is filled com-
pletely with COs, there is no place left and no need to mark
the end of CA.
Every telegram which this node is to receive or transmit is
represented by a CO. As well as the data and the time
stamp, this also contains a header, the telegram descriptor
(TD), in which the attributes of the communication object are
stored.
Fig. 27–3:
Forms of access:
r:
w:
i:
w0:
w1:
CM
r/i:
CM defines the type of telegram.
0: Inactive
1: Send
2: Receive
3: Fetch
4: Provide
5: Rx-All
6: rsvd
7: EoCA
As long as the CO is inactive (CM = 0) or locked (LCK =
TRUE), the BI accesses the first byte of the CO only by read-
ing. All other bytes are neither read nor written. The inactive
mode is suitable therefore for re-configuration of a CO on-
line; i.e. while the node is taking part in the bus traffic.
RSC
r/w0:
r/w1:
If the rescan bit has been set in a transmit object just pro-
Micronas
0
1
2
3
4
5
Extended Addr. Format (EXF is set)
20
28
12
4
read
write
init (BI halted or CM = inactive)
clear
set
7
CM
Extended and Standard TD Map
DLC
Communication Mode
Mode.
Inactive. No participation in the bus traffic.
Send data.
Receive data.
Fetch data via remote frame.
Have data fetched via remote frame.
Receive every telegram.
Don’t use (provis. EoCA).
End of Communication Area.
Rescan
Don’t rescan.
Rescan.
6
ID
5
RSC
4
ID
ID
ID
MID
TIE
0
3
EXF
OW
RIE
2
RSR
rsvd
SR
1
June 12, 2003; 6251-579-1PD
ACC
LCK
TS
21
13
5
0
The COs are entered in order of priority into the CA. This
starts with the highest priority (the lowest identifier). The
identifier defines the priority of a Tg. If the first eleven bits of
an ext. Tg are the same as the identifier of a std. Tg, the Tg
with standard identifier has higher priority.
27.2.4.1. Telegram Descriptor (TD)
The telegram descriptor is 6 bytes (TD0 to TD5) long and
forms the beginning of a CO. Telegrams with std. and ext.
identifiers have different TDs. They differ only in the length of
the identifiers. 18 bits therefore are not allocated in the TD of
a std. Tg. They cannot be used by the application because
they are overwritten by the reception of a Tg.
cessed, the search for active Tx objects is started at the
beginning of the communication area. Otherwise, the search
continues at this transmit object until the end of the CA is
reached. From there, the system jumps back to the begin-
ning of the CA.
MID
r/w0:
r/w1:
If MID has been deleted, the identifier received is compared
bit-by-bit with the identifier from the telegram descriptor, i.e.
the entire identifier must be the same so that the telegram
received is transferred into this CO. If MID has been set, only
bits which are allowed in the ID mask register of the GCS are
used for the comparison.
OW
r/w0:
r/w1:
When OW is set, the com. object may be overwritten even if
the application has not yet fetched the contents (TS set). The
BI must of course obtain right of access (LCK deleted).
LCK
r/w0:
r/w1:
Lock determines the right of access for the BI.
ID
r/i:
0
1
2
3
4
5
Standard Addr. Format (EXF is deleted)
28
20
7
CM
ID
DLC
6
don’t use
Mask Identifier
Don’t mask.
Mask.
Overwrite
Don’t overwrite.
Overwrite.
Lock
BI has right of access.
BI does not has right of access.
Identifier
Identifier.
18
5
RSC
don’t use
4
ID
MID
CDC 32xxG-C
TIE
3
don’t use
EXF
OW
RIE
2
RSR
rsvd
SR
1
ACC
LCK
TS
21
175
0