MC912DG128ACPV Freescale Semiconductor, MC912DG128ACPV Datasheet - Page 322

• Manufacturer Part Number: MC912DG128ACPV
• Description: IC MCU 128K FLASH 8MHZ 112-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC12r

Specifications of MC912DG128ACPV

• Core Processor: CPU12
• Core Size: 16-Bit
• Speed: 8MHz
• Connectivity: CAN, I²C, SCI, SPI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 16x8/10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 112-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Inter IC Bus
17.7.7 Arbitration Lost
Technical Data
322
receive mode. The slave will drive SCL low in-between byte transfers,
SCL is released when the IBDR is accessed in the required mode.
In slave transmitter routine, the received acknowledge bit (RXAK) must
be tested before transmitting the next byte of data. Setting RXAK means
an 'end of data' signal from the master receiver, after which it must be
switched from transmitter mode to receiver mode by software. A dummy
read then releases the SCL line so that the master can generate a STOP
signal.
If several masters try to engage the bus simultaneously, only one master
wins and the others lose arbitration. The devices which lost arbitration
are immediately switched to slave receive mode by the hardware. Their
data output to the SDA line is stopped, but SCL is still generated until the
end of the byte during which arbitration was lost. An interrupt occurs at
the falling edge of the ninth clock of this transfer with IBAL=1 and
MS/SL=0. If one master attempts to start transmission while the bus is
being engaged by another master, the hardware will inhibit the
transmission; switch the MS/SL bit from 1 to 0 without generating STOP
condition; generate an interrupt to CPU and set the IBAL to indicate that
the attempt to engage the bus is failed. When considering these cases,
the slave service routine should test the IBAL first and the software
should clear the IBAL bit if it is set.
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Inter IC Bus
MC68HC912DT128A — Rev 4.0
MOTOROLA