Users Manual

R01UH0823EJ0110 Rev.1.10 Page 1198 of 1852
Nov 30, 2020
RX23W Group 36. CAN Module (RSCAN)
36. CAN Module (RSCAN)
36.1 Overview
This MCU incorporates the Controller Area Network (CAN) module with one channel of CAN protocol controller
conforming to the ISO 11898-1 standard.
Table 36.1 shows the CAN module specifications. Figure 36.1 shows the
CAN module block diagram.
Table 36.2 lists the I/O pins of the CAN module.
In this section, the following variables indicate the number of registers.
• j (j = 0 to 15): Receive rule entry register number
(GAFLIDLj, GAFLIDHj, GAFLMLj, GAFLMHj, GAFLPLj, GAFLPHj)
• m (m = 0, 1): Receive FIFO buffer number
• n (n = 0 to 15): Receive buffer number
• p (p = 0 to 3): Transmit buffer number
• r (r = 0 to 127): RAM test register (RPGACCr) number
Table 36.1 CAN Module Specifications (1/2)
Item Specification
Number of channels 1
Protocol ISO 11898-1 compliant
Communication speed
• Maximum 1 Mbps
CAN bit time = CANTq × Tq count per bit
Tq: Time quantum
fCAN: Frequency of CAN clock source (selected by the GCFGL.DCS bit)
Buffer 20 buffers in total
• Individual buffers: 4 buffers (4 buffers for one channel)
Transmit buffer: 4 buffers per a channel
• Shared buffers: 16 buffers
Receive buffer: 0 to 16 buffers
Receive FIFO buffer: 2 FIFO buffers (up to 16 buffers allocatable to each)
Transmit/receive FIFO buffer: A FIFO buffer per a channel (up to 16 buffers allocatable to each)
Reception function
• Receives data frames and remote frames.
• Selects ID format (standard ID, extended ID, or both IDs) to be received.
• Sets interrupt enable/disable for each FIFO.
• Mirror function (to receive messages transmitted from the own CAN node)
• Timestamp function (to record message reception time as a 16-bit timer value)
Reception filter function
• Selects receive messages according to 16 receive rules.
• Sets the number of receive rules (0 to 16) for each channel.
• Acceptance filter processing: Sets ID and mask for each receive rule.
• DLC filter processing: Sets DLC check value for each receive rule.
Receive message
transfer function
• Routing function to transfer receive messages to arbitrary destinations
(can be transferred to up to 2 buffers).
Transfer destination: Receive buffer, receive FIFO buffer, and transmit/receive FIFO buffer
• Label addition function
Stores label information together when storing a message in a receive buffer and FIFO buffer.
Transmission function
• Transmits data frames and remote frames.
• Selects ID format (standard ID, extended ID, or both IDs) to be transmitted.
• Sets interrupt enable/disable for each transmit buffer and transmit/receive FIFO buffer.
• Selects ID priority transmission or transmit buffer number priority transmission.
• Transmit abort function (completion of the abort can be confirmed with the flag)
• One-shot transmission function
Interval transmission
function
Sets message transmission interval time (transmit mode of transmit/receive FIFO buffers)
Communication speed (CAN bit time clock)
1
CAN bit time
---------------------------------=
CANTq
CFGL.BRP[9:0] bits 1
+
fCAN
--------------------------------------------------------------=