MCP2515-I/SO Microchip Technology, MCP2515-I/SO Datasheet - Page 32

• Manufacturer Part Number: MCP2515-I/SO
• Description: IC CAN CONTROLLER W/SPI 18SOIC
• Manufacturer: Microchip Technology

Specifications of MCP2515-I/SO

• Package / Case: 18-SOIC (7.5mm Width)
• Controller Type: CAN Interface
• Interface: SPI
• Voltage - Supply: 2.7 V ~ 5.5 V
• Current - Supply: 10mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Product: Controller Area Network (CAN)
• Number Of Transceivers: 1
• Data Rate: 1 Mbps
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Supply Current (max): 10 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Supply Voltage Range: 2.7V To 5.5V
• Driver Case Style: SOIC
• No. Of Pins: 18
• Operating Temperature Range: -40°C To +85°C
• Filter Terminals: SMD
• Supply Voltage Min: 2.7V
• Rohs Compliant: Yes
• Clock Frequency: 40MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: MCP2515DM-BM - BOARD DEMO FOR MCP2515/51MCP2515DM-PTPLS - BOARD DAUGHTER PICTAIL MCP2515MCP2515DM-PCTL - BOARD DEMO FOR MCP2515DV251001 - KIT DEVELOPMENT CAN MCP2510
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

MCP2515
4.5
The message acceptance filters and masks are used to
determine if a message in the message assembly buf-
fer should be loaded into either of the receive buffers
(see
received into the MAB, the identifier fields of the mes-
sage are compared to the filter values. If there is a
match, that message will be loaded into the appropriate
receive buffer.
4.5.1
When receiving standard data frames (11-bit identifier),
the MCP2515 automatically applies 16 bits of masks
and
identifiers to the first 16 bits of the data field (data bytes
0 and 1).
apply to extended and standard data frames.
Data byte filtering reduces the load on the MCU when
implementing Higher Layer Protocols (HLPs) that filter
on the first data byte (e.g., DeviceNet™).
4.5.2
The filter masks (see Register 4-14 through Register 4-
17) are used to determine which bits in the identifier are
examined with the filters. A truth table is shown in
Table 4-2
FIGURE 4-4:
DS21801F-page 32
* The two MSb (EID17 and EID16) mask and filter bits are not used.
ID10
ID10
Figure
filters
Message Acceptance Filters and
Masks
that indicates how each bit in the identifier is
Figure 4-4
DATA BYTE FILTERING
FILTER MATCHING
11-bit ID Standard frame
4-5). Once a valid message has been
normally
illustrates how masks and filters
MASKS AND FILTERS APPLY TO CAN FRAMES
associated
Masks and Filters apply to the entire 29-bit ID field
with
ID0
ID0
extended
EID17
*
Standard Data Frame
Extended Frame
Data Byte 0
compared to the masks and filters to determine if the
message should be loaded into a receive buffer. The
mask essentially determines which bits to apply the
acceptance filters to. If any mask bit is set to a zero,
that bit will automatically be accepted, regardless of the
filter bit.
TABLE 4-2:
As shown in the receive buffers block diagram
(Figure
filter mask RXM0) are associated with RXB0. Filters
RXF2, RXF3, RXF4, RXF5 and mask RXM1 are
associated with RXB1.
Mask Bit n
Note:
0
1
1
1
1
16-bit data filtering *
4-2), acceptance filters RXF0 and RXF1 (and
X = don’t care
Filter Bit n
FILTER/MASK TRUTH TABLE
X
0
0
1
1
© 2010 Microchip Technology Inc.
Message
Identifier
Data Byte 1
bit
X
0
1
0
1
Reject bit n
Accept or
Accept
Accept
Accept
Reject
Reject
EID0