Renesas SH7262 R5S72620 User Manual

Page of 2152
 
Section 20   Controller Area Network 
Page 984 of 2108 
 
R01UH0134EJ0400  Rev. 4.00 
 
 Sep 
24, 
2014 
SH7262 Group, SH7264 Group
Important: LongWord (32-bit) accesses are converted into two consecutive word (16-bit) 
accesses by the bus interface. 
  Micro Processor Interface (MPI) 
The MPI allows communication between the Renesas CPU and this module’s 
registers/mailboxes to control the memory interface. It also contains the Wakeup Control logic 
that detects the CAN bus activities and notifies the MPI and the other parts of this module so 
that this module can automatically exit the Sleep mode. 
It contains registers such as MCR, IRR, GSR and IMR. 
 
  Mailbox 
The Mailboxes consists of RAM configured as message buffers and registers. There are 32 
Mailboxes, and each mailbox has the following information. 
<RAM> 
 
CAN message control (identifier, rtr, ide,etc) 
 
CAN message data (for CAN Data frames) 
 
Local Acceptance Filter Mask for reception 
<Registers> 
 
CAN message control (dlc) 
 
Time Stamp for message reception/transmission 
 
3-bit wide Mailbox Configuration, Disable Automatic Re-Transmission bit, Auto-
Transmission for Remote Request bit, New Message Control bit 
 
Tx-Trigger Time 
 
  Mailbox Control 
The Mailbox Control handles the following functions. 
 
For received messages, compare the IDs and generate appropriate RAM addresses/data to 
store messages from the CAN Interface into the Mailbox and set/clear appropriate registers 
accordingly. 
 
To transmit event-triggered messages, run the internal arbitration to pick the correct 
priority message, and load the message from the Mailbox into the Tx-buffer of the CAN 
Interface and set/clear appropriate registers accordingly. In the case of time-triggered 
transmission, compare match of Tx-Trigger time invoke loading the messages. 
 
Arbitrates Mailbox accesses between the CPU and the Mailbox Control. 
 
Contains registers such as TXPR, TXCR, TXACK, ABACK, RXPR, RFPR, UMSR and 
MBIMR.