MPC563XM Reference Manual, Rev. 1
Freescale Semiconductor
235
Preliminary—Subject to Change Without Notice
NOTE
Read Wait State Control is handled within the BIU.
000 - No additional wait states are added. (250 kHz < Operating Frequency
< 45 MHz)
001 - One additional wait state is added. (45 MHz < Operating Frequency <
90 MHz)
010 - Two additional wait states are added. (90 MHz < Operating Frequency
< 133 MHz)
011 - Three additional wait states are added. (Not needed for spec frequency
range of c90fl)
100 - Four additional wait states are added. (Not needed for spec frequency
range of c90fl)
101 - Five additional wait states are added. (Not needed for spec frequency
range of c90fl)
110 - Six additional wait states are added. (Not needed for spec frequency
range of c90fl)
111 - Seven additional wait states are added. (Not needed for spec frequency
range of c90fl)
NOTE
For Address Pipelined Control and Read Wait State Control, it should be
noted that pipelining can only be utilized at 53 MHz to 63 MHz, or 90 MHz
to 125 MHz. Thus it is possible to achieve better overall performance (due
to pipelining) at 125 MHz than executing reads (non-pipelined by design) at
133 MHz.
WARNING
For frequencies that correspond to access times approaching the c90fl read
access time (22 nS), care must be taken when doing pipelining, as a loss of
data may occur due to the data from the pipelined read request occurring
prior to the initial read request data capture. This occurs at frequencies
from 45 MHz (22 nS clock period) to 53 MHz (19 nS clock period). It is
recommended that at these frequencies pipelining not be used.
10.3.6.9
Bus Interface Unit 1 Register
The Bus Interface Unit 1 Register (BIU1) provides a means for BIU specific information, or BIU
configuration information to be stored.
10.3.6.9.1
BIU1 Register
The following field and bit descriptions fully define the BIU1 register (
).