MPC555
/
MPC556
EXTERNAL BUS INTERFACE
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
9-45
Figure 9-32 Retry Transfer Timing–External Arbiter
When the MPC555
/ MPC556 initiates a burst access, the bus interface recognizes the
RETRY assertion as a retry termination only if it detects it before the first data beat was
acknowledged by the slave device. When the RETRY signal is asserted as a termina-
tion signal on any data beat of the access after the first (being the first data beat ac-
knowledged by a normal TA assertion), the MPC555
/ MPC556 recognizes RETRY as
a transfer error acknowledge.
CLKOUT
ADDR[0:31]
TS
BR (output)
BG
BB
Data
TA
RD/WR
BURST
TSIZ[0:1]
RETRY (input)
ADDR
ADDR
Allow External
Master to Gain the Bus
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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