IBM PowerPC 405GP User Manual

14.2.2 Decompression Address Decode Definition Registers (DCPO_ADDRO-
DCPO_ADDR1 )
DCPO_ADDRO-DCPO_ADDR1 each define an address space used by the decompression controller
for compressed instructions, and for uncompressed accesses thafare passed to a memory controller.
DRBA
\0
*
9\10 11112
15
116
t
DRS
Figure 14-2. Decompression Address Decode Definition Registers (DCPO_ADDRO-
DCPO_ADDR1
)
0:9
DRBA Decode Region Base Address
High-order decode region address bits
10:11
Reserved
12:15 DRS
Decode Region Size
0000-0100 Reserved
0101 4MB
01108MB
0111 16MB
1000 32MB
1001 64MB
1010 128MB
1011 256MB
1100512MB
11011GB
11102GB
1111 4GB
16:30 Reserved
31 OREN Enable Decode Region
o Decoding is disabled for region
1 Decoding is
enabled for region.
14.2.3 Decompression Configuration Register (DCPO_CFG)
DCPO_CFG is used to configure the operation of the decompression controller.
DCPO_CFG[IKB]
must be set to ° to enable decompression. The value of this field determines
whether the
UO storage attribute is recognized; the storage attribute must be recognized for
decompression to occur.
Preliminary Decompression Controller Operation
OREN
*
\31\
14-5

IBM PowerPC 405GP Specifications

General

Brand	IBM
Model	PowerPC 405GP
Category	Computer Hardware
Language	English