MPC555
/
MPC556
EXTERNAL BUS INTERFACE
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
9-48
Figure 9-34 Basic Flow of an External Master Read Access
External Master
Request Bus (BR)
Receives Bus Grant (BG) From Arbiter
Asserts Bus Busy (BB) if No Other Master is Driving
Assert Transfer Start (TS)
Drives Address and Attributes
Receives Address
Returns Data
Asserts Transfer Acknowledge (TA)
Receives Data
Address in Internal
Memory Map
No
Yes
Asserts CSx
If In Range
Memory
Controller
MPC555 /
MPC556
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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