MC68HC000RC12 Datasheet, PDF (42/189 Pages) Freescale Semiconductor, Inc – 8-/16-/32-Bit Microprocessors User’s Manual

Freescale Semiconductor, Inc.
BUS MASTER
ADDRESS THE DEVICE
1) PLACE FUNCTION CODE ON FC2–FC0
2) PLACE ADDRESS ON A23–A0
3) ASSERT ADDRESS STROBE (AS)
4) SET R/W TO WRITE
5) PLACE DATA ON D0–D7
6) ASSERT LOWER DATA STROBE (LDS)
OR DS
TERMINATE OUTPUT TRANSFER
1) NEGATE LDS OR DS
2) NEGATE AS
3) REMOVE DATA FROM D7-D0
4) SET R/W TO READ
SLAVE
INPUT THE DATA
1) DECODE ADDRESS
2) STORE DATA ON D7–D0
3) ASSERT DATA TRANSFER
ACKNOWLEDGE (DTACK)
TERMINATE THE CYCLE
1) NEGATE DTACK
START NEXT CYCLE
Figure 4-3. Byte Write-Cycle Flowchart
CLK
FC2–FC0
A23–A0
S0 S1 S2 S3 S4 S5 S6 S7 S0 S1 S2 S3 S4 S5 S6 S7 S0 S1 S2 S3 S4 S5 S6 S7
AS
LDS
R/W
DTACK
D7–D0
ODD BYTE WRITE
ODD BYTE WRITE
EVEN BYTE WRITE
Figure 4-4. Write-Cycle Timing Diagram
4-4
M68000 8-/16-/32-BIT MICROPROCESSORS USER'S MANUAL
MOTOROLA
For More Information On This Product,
Go to: www.freescale.com