M16C Datasheet, PDF (172/262 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Preliminary Specifications REV.B
Mitsubishi microcomputers
Specifications in this manual are tentative and subject to change.
M16C / 6N Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
CAN Module
In the 'Basic CAN' mode, two exceptions regarding the message control register and the general configura-
tion concept exist:
1. CAN Frame Type Tolerance
In the 'normal operation mode', decide if an activated slot should handle 'data' or 'remote' frames. It is not
possible to receive 'data' frames and 'remote' frames in the same slot without a reconfiguration process by
the CPU.
In case of the operation with a 'Basic CAN' channel, this behavior is not tolerable, because both frame types
must be handled without CPU interaction.
Therefore, the 'Basic CAN' feature enables message slots #14 and #15 to receive both types of CAN
frames, 'data'- and 'remote' frames.
2. CAN Frame Type Indication
In the 'normal operation mode', the Extended ID register (C0IDR/C1IDR) dictates the type of frames, i.e.
Extended or Standard, which can be handled by the message box. As described in the upper section for the
'Basic CAN' slots, it is possible to receive both frame types irrespective of the slot configuration. Therefore,
the CAN module provides the frame type information in the corresponding message control register.
Because the 'RemActive' information is not needed for the 'Basic CAN' slot function, the frame type informa-
tion is mapped to this location (refer to section 'CAN Message Control Register'). The content of this bit
corresponds to the frame type stored last in this slot location .
CAN Extended ID Register
CAN ExtID Register
(b15)
b7 b6
(b8)
b0 b7
b0
Symbol
C0IDR
C1IDR
Address
0219₁₆, 0218₁₆
0239₁₆, 0238₁₆
When reset
0000₁₆
0000₁₆
Function
Values that can be set for each bit
ExtID Bits
0: Mailbox handles standard
Each bit corresponds with the appropriate message
identifiers.
mailbox.
1: Mailbox handles extended
ID-format assignment for each message mailbox
identifiers.
Note: These bits can not be set in Reset/Initialization Mode.
RW
OO
Figure 18-9. Structure of CAN extended ID register
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