
Hardware Description
MFC 2000 Multifunctional Peripheral Controller 2000
100723A
Conexant
4-27
Table 4-5. Access Modes for Reading ROM
ROM Access
Mode
Data Type
Cache Memory
Wait States
Notes
8-bit non-
interleave
instruction
Cache enabled
and Cache miss
w,w,w,w,w,w,w,w
w,w,w,w,w,w,w,w
(16 sequential accesses)
This is cache burst access. Save the address decoding
cycle for all accesses except the first access.
16-bit non-
interleave
instruction
Cache enabled
and Cache miss
w,w,w,w,w,w,w,w
(8 sequential accesses)
This is cache burst access. Save the address decoding
cycle for all accesses except the first access.
8-bit non-
interleave
instruction
Cache disabled
w
If the sequential access occurs, save the address decoding
cycle for all accesses except the first access.
16-bit non-
interleave
instruction
Cache disabled
w
If the sequential access occurs, save the address decoding
cycle for all accesses except the first access.
8-bit non-
interleave
data
Not applied
w
If the sequential access occurs, save the address decoding
cycle for all accesses except the first access.
16-bit non-
interleave
data
Not applied
w
If the sequential access occurs, save the address decoding
cycle for all accesses except the first access.
16-bit 2-way
interleave
instruction
Cache enabled
and Cache miss
w, s,
w-s-1, s,
w-s-1, s,
w-s-1, s
(8 sequential accesses)
This is cache burst access. 0 or 1 wait state is
programmable and depends on the CPU clock frequency
and the ROM speed. If ‘w-s-1’ is less than 1, it will be forced
to 1.
16-bit 2-way
interleave
instruction
Cache disabled
w, s,
w-s-1, s,
w-s-1, s,
w-s-1, s
(one interleave access
sequence)
The actual sequential
access length is dynamic.
0 or 1 wait state is programmable and depends on the CPU
clock frequency and the ROM speed. If the starting address
of the sequential access is not lined up with the octal
address boundary of the interleave access, the partial
interleave access sequence should be done. Then, restart
the interleave access sequence at the octal address
boundary of the interleave access. Even if the stopping
address of the sequential access is not lined up with the
octal address boundary of the interleave access, the access
sequence must be stopped immediately at anywhere. If ‘w-
s-1’ is less than s, it will be forced to s.
16-bit 2-way
interleave
data
Cache enabled
and Cache miss
w, s,
w-s-1, s,
w-s-1, s,
w-s-1, s
(one interleave access
sequence)
The actual sequential
access length is dynamic.
0 or 1 wait state is programmable and depends on the CPU
clock frequency and the ROM speed. If the starting address
of the sequential access is not lined up with the octal
address boundary of the interleave access, the partial
interleave access sequence should be done. Then, restart
the interleave access sequence at the octal address
boundary of the interleave access. Even if the stopping
address of the sequential access is not lined up with the
address boundary of the interleave access, the access
sequence must be stopped immediately at anywhere. If ‘w-
s-1’ is less than s, it will be forced to s.