MC68306 Motorola, MC68306 Datasheet - Page 38

• Manufacturer Part Number: MC68306
• Description: Integrated EC000 Processor
• Manufacturer: Motorola

3-6
FC2–FC0
*INTERNAL SIGNAL ONLY
D15–D8
A31–A1
DTACK
D7–D0
1) PLACE FUNCTION CODE ON FC2–FC0
2) PLACE ADDRESS ON ADDRESS BUS
3) ASSERT ADDRESS STROBE (AS)
4) SET R/W TO WRITE
5) PLACE DATA ON D0–D7 OR D15–D8
6) ASSERT UPPER DATA STROBE (UDS)
1) NEGATE UDS AND LDS
2) NEGATE AS
3) REMOVE DATA FROM D7-D0 OR
4) SET R/W TO READ
UDS
CLK
LDS
R/W
(ACCORDING TO INTERNAL A0)
OR LOWER DATA STROBE (LDS)
(BASED ON INTERNAL A0)
D15-D8
TERMINATE OUTPUT TRANSFER
A0
AS
*
ADDRESS THE DEVICE
START NEXT CYCLE
Figure 3-7. Word and Byte Write Cycle Timing Diagram
BUS MASTER
S0 S1 S2 S3 S4 S5 S6 S7 S0 S1 S2 S3 S4 S5 S6 S7 S0 S1 S2 S3 S4 S5 S6 S7
WORD WRITE
Figure 3-6. Byte Write Cycle Flowchart
MC68306 USER'S MANUAL
ODD BYTE WRITE
1) DECODE ADDRESS
2) LATCH DATA ON D7–D0 IF LDS IS
3) ASSERT DATA TRANSFER
1) NEGATE DTACK
ASSERTED. LATCH DATA ON D15–D8
IF UDS IS ASSERTED
ACKNOWLEDGE (DTACK)
TERMINATE THE CYCLE
INPUT THE DATA
EVEN BYTE WRITE
SLAVE
MOTOROLA