MC908AZ32ACFU Freescale Semiconductor, MC908AZ32ACFU Datasheet - Page 264

• Manufacturer Part Number: MC908AZ32ACFU
• Description: IC MCU 32K FLASH 8.4MHZ 64-QFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908AZ32ACFU

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: CAN, SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 40
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 15x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

MSCAN Controller (MSCAN08)
24.3 External Pins
The MSCAN08 uses two external pins, one input (RxCAN) and one output (TxCAN). The TxCAN output
pin represents the logic level on the CAN: 0 is for a dominant state, and 1 is for a recessive state.
A typical CAN system with MSCAN08 is shown in
Each CAN station is connected physically to the CAN bus lines through a transceiver chip. The
transceiver is capable of driving the large current needed for the CAN and has current protection against
defected CAN or defected stations.
24.4 Message Storage
MSCAN08 facilitates a sophisticated message storage system which addresses the requirements of a
broad range of network applications.
24.4.1 Background
Modern application layer software is built under two fundamental assumptions:
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1. Any CAN node is able to send out a stream of scheduled messages without releasing the bus
2. The internal message queue within any CAN node is organized as such that the highest priority
between two messages. Such nodes will arbitrate for the bus right after sending the previous
message and will only release the bus in case of lost arbitration.
message will be sent out first if more than one message is ready to be sent.
CAN_H
TXCAN
CAN NODE 1
TRANSCEIVER
CAN CONTROLLER
MCU
(MSCAN08)
MC68HC908AZ32A Data Sheet, Rev. 2
Figure 24-1. The CAN System
RXCAN
CAN_L
C A N BUS
Figure
CAN STATION 1
CAN NODE 2
24-1.
CAN NODE N
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