Philips Semiconductors
Cache Architecture
File: cache.fm5, modified 7/24/99
PRELIMINARY INFORMATION
5-13
5.7
PERFORMANCE EVALUATION
SUPPORT
The caches implement support for performance evalua-
tion. Several events that occur in the caches can be
counted using the TM1100 timer/counters, by selecting
the source CACHE1 and/or CACHE2, as described in
tracked simultaneously by using 2 timers.
The MMIO register MEM_EVENTS determines which
MEM_EVENTS.
Table 5-14 lists the events that can be
tracked
and
the
corresponding
values
for
the
MEM_EVENTS fields. Event1 selects the actual source
for the TIMER CACHE1 source. Event2 selects the
source for TIMER CACHE2.
5.8
MMIO REGISTER SUMMARY
Table 5-15 lists the MMIO registers that pertain to the op-
eration of TM1100’s instruction and data caches.
Table 5-14. Trackable Cache-Performance Events
Encoding
Event
0
No event counted
1
Instruction-cache misses
2
Instruction-cache stall cycles (including data-
cache stall cycles if both instruction-cache and
data-cache are stalled simultaneously)
3
Data-cache bank conicts
4
Data-cache read misses
5
Data-cache write misses
6
Data-cache stall cycles (that are not also instruc-
tion-cache stall cycles)
7
Data-cache copyback to SDRAM
8
Copyback buffer full
9
Data-cache write miss with all fetch units occu-
pied
10
Data cache stream miss
11
Prefetch operation started and not discarded
12
Prefetch operation discarded (because it hits in
the cache or there is no fetch unit available)
13
Prefetch operation discarded (because it hits in
the cache)
14–15
Reserved
31
0
3
7
11
15
19
23
27
MEM_EVENTS (r/w)
0x10 000C
0
Event2
MMIO_BASE
offset:
000 00000000000000000000
Event1
Figure 5-14. Format of the memory_events MMIO register.
Table 5-15. MMIO Register Summary
Name
Description
DRAM_BASE
Sets location of the DRAM aperture
DRAM_LIMIT
Sets size of the DRAM aperture
DRAM_CACHEABLE
_LIMIT
Divides DRAM aperture into cache-
able and non-cacheable portions
MEM_EVENTS
Selects which two events will be
counted by timer/counters
DC_LOCK_CTL
Data-cache locking enable and aper-
ture control.
DC_LOCK_ADDR
Sets low address of the data-cache
address lock aperture
DC_LOCK_SIZE
Sets size of the data-cache address
lock aperture
DC_PARAMS
Read-only register with data-cache
parameter information
IC_PARAMS
Read-only register with instruction-
cache parameter information
IC_LOCK_CTL
Instruction-cache locking enable
IC_LOCK_ADDR
Sets low address of the instruction-
cache address lock aperture
IC_LOCK_SIZE
Sets size of the instruction-cache
address lock aperture
MMIO_BASE
Sets location of the MMIO aperture