mcf5249 Freescale Semiconductor, Inc, mcf5249 Datasheet - Page 339

• Manufacturer Part Number: mcf5249
• Description: Coldfire Integrated Microprocessor
• Manufacturer: Freescale Semiconductor, Inc

Freescale Semiconductor, Inc.
MOVE.B (A7)+, MBCR;
MOVE.B CALLING,-(A7);Transmit the calling address, D0=R/W
MOVE.B (A7)+, MBDR;
IFREE MOVE.B MBSR,-(A7);Check the IBB bit of the MBSR.
;If it is clear, wait until it is set.
BTST.B #5, (A7)+;
BEQ.S IBFREE;
MBSR LEA.L MBSR,-(A7);Load effective address
BCLR.B #1,(A7)+;Clear the IIF flag
MOVE.B MBCR,-(A7);Push the address on stack,
BTST.B #5,(A7)+;check the MSTA flag
BEQ.S SLAVE;Branch if slave mode
MOVE.B MBCR,-(A7);Push the address on stack
BTST.B #4,(A7)+;check the mode flag
BEQ.S RECEIVE;Branch if in receive mode
MOVE.B MBSR,-(A7);Push the address on stack,
BTST.B #0,(A7)+;check ACK from receiver
BNE.B
END;If no ACK, end of transmission
TRANSMIT MOVE.B DATABUF,-(A7);Stack data byte
MOVE.B (A7)+, MBDR);Transmit next byte of data
Generation of STOP
A data transfer ends with a STOP signal generated by the “master’' device. A master transmitter can generate a STOP signal
after all the data has been transmitted. The following code is an example showing how a master transmitter generates a stop
condition.
MASTX
MOVE.B MBSR, -(A7); If no ACK, branch to end
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