米6体育平台手机版

SPRUJF1 November 2024 AM2612

ADVANCE INFORMATION

2.12 MCAN

The LaunchPad is equipped with a single MCAN Transceiver (TCAN1044VDRBTQ1) that is connected to the MCAN0 interface of the AM261x SoC. The MCAN Transceiver has two power inputs, VIO is the transceiver 3.3V system level shifting supply voltage and VCC is the transceiver 5V supply voltage. The SoC CAN data transmit data input is mapped to TXD of the transceiver and the CAN receive data output of the transceiver is mapped to the MCAN RX signal of the SoC.

AM261x CAN Transceiver and BoosterPack Header

Figure 2-20 CAN Transceiver and BoosterPack Header

The system has a 120Ω split termination on the CANH and CANL signals to improve EMI performance. Split termination improves the electromagnetic emissions behavior of the network by eliminating fluctuations in the bus common-mode voltages at the start and end of message transmissions.

The low and high level CAN bus input output lines are terminated to a three pin header.

The standby control signal is an AM261x SoC GPIO signal. The STB control input has a pullup resistor that is used to have the transceiver be in low-power standby mode to prevent excessive system power. Below is a table that shows the operating modes of the MCAN transceiver based on the STB control input logic.

Table 2-8 MCAN Transceiver Operating Modes

STB	Device Mode	Driver	Receiver	RXD Pin
High	Low current standby mode with bus wake-up	Disabled	Low-power receiver and bus monitor enable	High (recessive) until valid WUP is received
Low	Normal Mode	Enabled	Enabled	Mirrors bus state

MCAN1 is routed to the BoosterPack Header via a 2:1 mux. The mux selects whether PR1_PRU0 signals or MCAN signals are mapped to the BoosterPack Header. The Detailed BoosterPack modes are given in BoosterPack Chapter.

Table 2-9 MCAN BoosterPack Mux

BP_MUX_SW_S1	BP_MUX_SW_S0	Condition	Function of Mux
LOW	LOW	MCAN TX/RX Selected	Port A ↔ Port B/COM ↔NC
LOW	HIGH	PRU Signals Selected	Port A ↔ Port C/COM ↔NO
HIGH	LOW	PRU Signals Selected	Port A ↔ Port C/COM ↔NO
HIGH	HIGH	MCAN TX/RX Selected	Port A ↔ Port B/COM ↔NC