Nations Technologies Inc.
Tel
:
+86-755-86309900
:
info@nationstech.com
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
551
/
631
dramatically which will occupides lots of CPU resource. In this CAN controller, receive FIFOs and filter mechanism
are added as hardware support for CPU message processing and reduce real-time response requirement of CAN
message.
Figure 25-1 Topology of CAN network
CAN module
CAN module can automatically receive and send CAN messages, and supports standard identifiers (11 bits) and
extended identifiers (29 bits).
CAN working mode
Initialization, normal and sleep mode are three main working modes of CAN. The internal pull-up resistor of CANTX
pin is activated after hardware reset, and CAN works in sleep mode to reduce power consumption.
The software can set CAN_MCTRL.INIRQ and CAN_MCTRL.SLPRQ bit to configure CAN to enter
initialization
or
sleep
mode. The software reads values of the CAN_MSTS.INIAK or CAN_MSTS.SLPAK bit to confirm
whether the
initialization
or
sleep
mode is entered, at this time the internal pull-up resistor of the CANTX pin is
disabled.
CPU
CAN-
CTRL
CAN
transc
eiver
Rx
Tx
CAN_H
CAN_L
Node 1
Node 2
Node 3
Node n
..
.