Write Cycle; Write Cycle Flowchart; Basic Write Bus Cycle - Motorola ColdFire MCF5281 User Manual

Data Transfer Operation
• In S4, the external device can stop driving data after the rising edge of CLKOUT.
However data could be driven up to S5.
• For a read cycle, the external device stops driving data between S4 and S5.
States are described in Table 13-3.

13.4.4 Write Cycle

During a write cycle, the MCF5282 sends data to the memory or to a peripheral device. The
write cycle flowchart is shown in Figure 13-7.
MCF5282
1. Set R/W to write
2. Place address on A[31:0]
3. Assert TIP and SIZ[1:0]
4. Assert TS
5. Place data on D[31:0]
6. Negate TS
1. Sample TA low
2. Stop driving data from D[31:0]
1. Start next cycle
The write cycle timing diagram is shown in Figure 13-8.
CLKOUT
A[31:0], SIZ[1:0]
R/W
TIP
TS
CSn, BSn
D[31:0]
TA
Table 13-3 describes the six states of a basic write cycle.
13-8
Figure 13-7. Write Cycle Flowchart
S0 S1
Figure 13-8. Basic Write Bus Cycle
MCF5282 User's Manual
System
1. Decode address
2. Store data on D[31:0]
3. Assert TA
1. Negate TA
S2 S3 S4
Write
S5
MOTOROLA