Renesas RL78 Series - Page 1371

RL78/F13, F14 CHAPTER 18 CAN INTERFACE (RS-CAN LITE)
R01UH0368EJ0210 Rev.2.10 1339
Dec 10, 2015
• CFIGCV[2:0] Bits
These bits are used to specify the fraction of the transmit/receive FIFO buffer (the number of messages is
selected by the setting of the CFDC[2:0] bits) that must be filled for the FIFO buffer to generate a receive
interrupt request when the CFM[1:0] bits are set to B'00 (reception mode) and the CFIM bit is set to 0.
When the CFDC[2:0] bits are set to B'001 (4 messages), set the CFIGCV[2:0] bits to B'001, B'011, B'101, or
B'111.
Modify these bits only in global reset mode.
• CFIM Bit
This bit is used to select a transmit/receive FIFO interrupt source. Modify this bit only in global reset mode.
• CFDC[2:0] Bits
These bits are used to set the number of messages that can be stored in a single transmit/receive FIFO buffer.
If these bits are set to B'000, do not use any receive FIFO buffer. Modify these bits only in global reset mode.
• CFTXIE Bit
When this bit is set to 1 and the CFTXIF flag in the CFSTSk register is set to 1, a transmit/receive FIFO transmit
interrupt request is generated.
Modify this bit with the CFE bit set to 0 (no transmit/receive FIFO buffer is used).
• CFRXIE Bit
When this bit is set to 1 and the CFRXIF flag in the CFSTSk register is set to 1, a transmit/receive FIFO receive
interrupt request is generated.
Modify this bit with the CFE bit set to 0.
• CFE Bit
Setting this bit to 1 makes transmit/receive FIFO buffers available.
When this bit is set to 0 in transmit mode, if a message in the transmit/receive FIFO buffer is being transmitted
or to be transmitted next, the transmit/receive FIFO buffer becomes empty after completion of transmission,
CAN bus error detection, or arbitration lost. In other cases or in receive mode, the transmit/receive FIFO buffer
becomes empty immediately.
This bit is cleared to 0 when the following conditions are met.
• Receive mode: Global reset mode
• Transmit mode: Channel reset mode
Modify this bit only in the following mode.
• Receive mode: Global operating mode or global test mode
• Transmit mode: Channel communication mode or channel halt mode