maxq7666batm Maxim Integrated Products, Inc., maxq7666batm Datasheet - Page 28

• Manufacturer Part Number: maxq7666batm
• Description: 16-bit, Risc, Microcontroller-based, Smart Data-acquisition System
• Manufacturer: Maxim Integrated Products, Inc.

16-Bit, RISC, Microcontroller-Based,
Smart Data-Acquisition System
The basic functions covered by the CAN controller
include the use of 11-bit standard or 29-bit extended
acceptance identifiers, as programmed by the µC for
each message center, as shown in Figure 10. The CAN
unit stores up to 15 messages, with the standard 8-byte
data field in each message.
Each of the first 14 message centers is programmable
in either transmit or receive mode. Message center 15
is a receive-only message center with a buffer FIFO
arrangement to help prevent the inadvertent loss of
Figure 10. CAN 0 Controller Block Diagram
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CAN 0 CONTROLLER BLOCK DIAGRAM
DUAL PORT MEMORY
MESSAGE CENTERS 1–15
CONTROL/STATUS/MASK REGISTERS
MEDIA ARBITRATION 0–1 EXT GLOBAL MASK 0–3
MESSAGE CENTER 1
MESSAGE CENTER 2
MESSAGE CENTER 14
MESSAGE CENTER 15
MEDIA ID MASK 0–1
BUS TIMING 0–1
ARBITRATION 0–3
ARBITRATION 0–3
ARBITRATION 0–3
ARBITRATION 0–3
FORMAT
FORMAT
FORMAT
FORMAT
CAN Functional Description
DATA 0–7
DATA 0–7
DATA 0–7
DATA 0–7
STD GLOBAL MASK 0–1
MSG15 MASK 0–3
CAN PROCESSOR
CAN 0 PERIPHERAL REGISTERS
data when the µC is busy and is not allowed time to
retrieve the incoming message prior to the acceptance
of a second message into message center 15.
Message center 15 also utilizes an independent set of
mask registers and identification registers, only applied
once an incoming message has not been accepted by
any of the first 14 message centers. A second filter test
is also supported for all message centers (1–15) to
allow the CAN controller to use two separate 8-bit
media masks and media arbitration fields to verify the
contents of the first 2 bytes of data of each incoming
CAN 0 TRANSMIT ERROR
CAN 0 RECEIVE ERROR
CAN 0 MESSAGE 1–15
CONTROL REGISTERS
CAN 0 DATA POINTER
8-BIT
CAN 0 DATA BUFFER
Rx
CAN INTERRUPT
MAXQ7666
COUNTER
COUNTER
SOURCES
8-BIT
CHECK
Tx
CRC
BUS ACTIVITY WAKE-UP
DESTUFF
GENERATE
BIT
PROTOCOL
CRC
FSM
CAN
CAN 0 OPERATION CONTROL
CAN 0 INTERRUPT REGISTER
CAN 0 TRANSMIT MSG ACK
CAN 0 CONTROL REGISTER
CAN 0 RECEIVE MSG ACK
CAN 0 STATUS REGISTER
SHIFT
STUFF
Rx
BIT
TIMING
SHIFT
BIT
Tx
CANTXD
CANRXD