SH7280 Datasheet, PDF (1056/1726 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine family

Section 22 Controller Area Network (RCAN-ET) (SH7286 Only)
• Mailbox-0
Bit: 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
0
0 NMC 0
0
MBC[2:0]
0
0
0
0
DLC[3:0]
Initial value: 0
0
0
0
0
1
1
1
0
0
0
0
0
0
0
0
R/W: R
R R/W R
R R/W R/W R/W R
R
R
R R/W R/W R/W R/W
Note: MBC[1] of MB0 is always "1".
• Mailbox-15 to 1
Bit: 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
0
0 NMC ATX DART
MBC[2:0]
0
0
0
0
DLC[3:0]
Initial value: 0
0
0
0
0
1
1
1
0
0
0
0
0
0
0
0
R/W: R
R R/W R/W R/W R/W R/W R/W R
R
R
R R/W R/W R/W R/W
NMC (New Message Control): When this bit is set to ‘0’, the Mailbox of which the RXPR or
RFPR bit is already set does not store the new message but maintains the old one and sets the
UMSR correspondent bit. When this bit is set to ‘1’, the Mailbox of which the RXPR or RFPR bit
is already set overwrites with the new message and sets the UMSR correspondent bit.
Important: Please note that if a remote frame is overwritten with a data frame or vice versa could
be that both RXPR and RFPR flags (together with UMSR) are set for the same Mailbox. In this
case the RTR bit within the Mailbox Control Field should be relied upon.
NMC
0
1
Description
Overrun mode (Initial value)
Overwrite mode
ATX (Automatic Transmission of Data Frame): When this bit is set to ‘1’ and a Remote Frame
is received into the Mailbox DLC is stored. Then, a Data Frame is transmitted from the same
Mailbox using the current contents of the message data and updated DLC by setting the
corresponding TXPR automatically. The scheduling of transmission is still governed by ID
priority or Mailbox priority as configured with the Message Transmission Priority control bit
(MCR.2). In order to use this function, MBC[2:0] needs to be programmed to be ‘001’ (Bin).
When a transmission is performed by this function, the DLC (Data Length Code) to be used is the
one that has been received. Application needs to guarantee that the DLC of the remote frame
correspond to the DLC of the data frame requested.
Important: When ATX is used and MBC=001 (Bin) the filter for the IDE bit cannot be used
since ID of remote frame has to be exactly the same as that of data frame as the reply message.
Rev. 1.00 Jun. 26, 2008 Page 1026 of 1692
REJ09B0393-0100