Datasheet

dsPIC33EPXXXGM3XX/6XX/7XX
DS70000689D-page 296  2013-2014 Microchip Technology Inc.
FIGURE 21-1: CANx MODULE BLOCK DIAGRAM
21.2 Modes of Operation
The CANx module can operate in one of several
operation modes selected by the user. These modes
include:
• Initialization mode
• Disable mode
• Normal Operation mode
• Listen Only mode
• Listen All Messages mode
• Loopback mode
Modes are requested by setting the REQOP<2:0> bits
(CxCTRL1<10:8>). Entry into a mode is Acknowledged
by monitoring the OPMODE<2:0> bits (CxCTRL1<7:5>).
The module does not change the mode and the
OPMODEx bits until a change in mode is acceptable,
generally during bus Idle time, which is defined as at least
11 consecutive recessive bits.
Message Assembly
CAN Protocol
Engine
CxTX
Buffer
CxRX
RxF14 Filter
RxF13 Filter
RxF12 Filter
RxF11 Filter
RxF10 Filter
RxF9 Filter
RxF8 Filter
RxF7 Filter
RxF6 Filter
RxF5 Filter
RxF4 Filter
RxF3 Filter
RxF2 Filter
RxF1 Filter
RxF0 Filter
Transmit Byte
Sequencer
RxM1 Mask
RxM0 Mask
Control
Configuration
Logic
CPU
Bus
Interrupts
TRB0 TX/RX Buffer Control Register
RxF15 Filter
RxM2 Mask
TRB7 TX/RX Buffer Control Register
TRB6 TX/RX Buffer Control Register
TRB5 TX/RX Buffer Control Register
TRB4 TX/RX Buffer Control Register
TRB3 TX/RX Buffer Control Register
TRB2 TX/RX Buffer Control Register
TRB1 TX/RX Buffer Control Register
DMA Controller