Datasheet

Bus Operation
6-14 MCF5206e USER’S MANUAL MOTOROLA
Figure 6-6 is a flowchart for write transfers to 8-, 16-, or 32-bit ports. Bus operations are
similar for each case and vary only with the size indicated, the portion of the data bus used
for the transfer and the specific number of cycles needed for each transfer.
Figure 6-6. Byte-, Word-, and Longword-Write Transfer Flowchart
MCF5206e SYSTEM
1. DRIVE ADDRESS ON A[27:0]
2. DRIVE R/W
TO WRITE (R/W = 0)
3. DRIVE SIZ[1:0] TO INDICATE BYTE, WORD OR LONGWORD
4. DRIVE TT[1:0] AND ATM TO INDICATE APPROPRIATE
ACCESS TYPE
5. ASSERT TS
FOR ONE CLK CYCLE
1. NEGATE TS
2. DRIVE ATM TO INDICATE APPROPRIATE ACCESS TYPE
3. DRIVE DATA ON APPROPRIATE BYTE LANES BASED ON
SIZ[1:0], A[1:0] AND PORT SIZE
1. RECOGNIZE THE TRANSFER IS DONE
2. THREE-STATE D[31:0]
1. DECODE ADDRESS AND SELECT THE APPROPRIATE
SLAVE DEVICE.*
2. CAPTURE DATA FROM THE APPROPRIATE BYTE LANES
BASED ON SIZ[1:0], A[1:0] AND PORT SIZE
3. ASSERT TA
FOR ONE CLK CYCLE
*TO INSERT WAIT STATES, TA IS DRIVEN NEGATED.
Fr
eescale S
emiconduct
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, I
Freescale Semiconductor, Inc.
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