Datasheet

Bus Operation
MOTOROLA MCF5206e USER’S MANUAL 6-11
Figure 6-4 is a flowchart for read 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 6-4. Byte-, Word-, and Longword-Read Transfer Flowchart
MCF5206e SYSTEM
1. DRIVE ADDRESS ON A[27:0]
2. DRIVE R/W
TO READ (R/W = 1)
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. DECODE ADDRESS AND SELECT THE APPROPRIATE
SLAVE DEVICE.*
2. DRIVE DATA ON APPROPRIATE BYTE LANES BASED ON
SIZ[1:0], A[1:0] AND PORT SIZE
3. ASSERT TA
FOR ONE CLK CYCLE
1. NEGATE TS
2. DRIVE ATM TO INDICATE APPROPRIATE ACCESS TYPE
AND MODE
1. REGISTER DATA
2. RECOGNIZE THE TRANSFER IS DONE
*TO INSERT WAIT STATES, TA IS DRIVEN NEGATED.
Fr
eescale S
emiconduct
or
, I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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