MC68306FC16 Datasheet, PDF (38/191 Pages) Motorola, Inc – Integrated EC000 Processor

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