MOTOROLA
Chapter 3. Device Programming
3-61
13
CF_HOLD
0
L2 tag address hold. This bit controls the hold time of the
address, TV, and DIRTY_OUT signals with respect to the
rising edge (negation) of TWE.
0
Synchronous tag RAM configurations. No hold time (0
clock cycles). TV is always driven during tag reads.
1
Asynchronous tag RAM configurations. Tag address, TV,
and DIRTY_OUT are held valid for one clock cycle after
TWE is negated. TV is released to high-impedance
during tag reads.
12
CF_INV_MODE
0
L2 invalidate mode enable. When L2 invalidate mode is
enabled, any 60x transaction on the 60x bus causes the L2 to
invalidate the tag entry indexed by the 60x address. Invalidate
mode is used to initialize the tag contents. Note that this bit
has no effect on the external L2 cache controller operation.
See Section 5.2.2, “L2 Cache Line Status,” for more
information.
0
L2 invalidate mode is disabled.
1
L2 invalidate mode is enabled.
11
CF_RWITM_FILL
0
L2 read-with-intent-to-modify line-fill disable. This bit controls
the response of the internally-controlled L2 cache to
read-with-intent-to-modify (RWITM) misses. Note that this bit
has no effect on the external L2 cache controller operation.
See Section 5.3, “L2 Cache Response to Bus Operations,” for
more information.
0
The internally-controlled L2 cache performs a line-fill
when a RWITM miss occurs.
1
The internally-controlled L2 cache does not perform a
line-fill when a RWITM miss occurs.
10–9
CF_L2_HIT_DELAY
11
L2 cache hit delay. These bits control the number of clock
cycles from the assertion of TS until HIT is valid. See
Section 5.4.2.1, “CF_L2_HIT_DELAY,” for more information.
00
Reserved
01
1 clock cycle
10
2 clock cycles
11
3 clock cycles
8
CF_TWO_BANKS
0
L2 cache banks. This bit specifies the number of banks of L2
data RAM. See Section 5.1.6, “Two-Bank Support,” for more
information.
0
1 SRAM bank
1
2 SRAM banks
7
CF_FAST_CASTOUT
0
Fast L2 castout timing
0
Normal L2 castout timing. TV is released to
high-impedance during tag reads.
1
Fast L2 castout timing for improved performance when
using synchronous write tag RAMs. TV is always driven
during tag reads.
Table 3-37. Bit Settings for PICR2—0xAC (Continued)
Bit
Name
Reset
Value
Description