MOTOROLA
5
Since there are 8 sectors of 128 words each, in the internal program RAM, the 32 bit ad-
dress is divided into the following two fields:
• 7 LSBs for the word displacement or offset in the sector
• 25 MSBs for the tag
The sector placement algorithm is fully associative so that each external program memory
sector could be placed in any of the 8 internal program RAM sectors, essentially making
it an eight-way fully associative cache.
A 25-bit tag is associated with every one of the eight internal program memory RAM sec-
tors. When the cache controller searches for a tag equal to the tag field of the current ad-
dress, it compares it to the eight tags in parallel using the eight comparators.
Each word in each cache sector is associated with a cache-word-valid-bit (or valid-bit),
that specifies whether the data in that word has already been fetched from external mem-
ory and is therefore valid. There are a total of 1024 valid-bits, arranged as eight banks of
128 valid-bits each, one bank for every sector. Note that the valid-bits are not available to
the user for direct use. They are cleared by the processor RESET to indicate that the
PRAM context has not been initialized.
32 bit address
25 bit Tag Field
7 bits
comparator 0
tag 0
128 valid
bits for
sector 0
hit/miss
Figure 2 - Cache Controller Block Diagram
Tag Values
Summary of Contents for DSP96002
Page 3: ...1 2 DSP96002 USER S MANUAL MOTOROLA ...
Page 38: ...MOTOROLA DSP96002 USER S MANUAL 3 15 Figure 3 4 Modulo Arithmetic Unit Block Diagram ...
Page 39: ...3 16 DSP96002 USER S MANUAL MOTOROLA ...
Page 53: ...4 14 DSP96002 USER S MANUAL MOTOROLA ...
Page 76: ...MOTOROLA DSP96002 USER S MANUAL 5 23 Figure 5 8 Address Modifier Summary ...
Page 86: ...6 10 DSP96002 USER S MANUAL MOTOROLA ...
Page 101: ...MOTOROLA DSP96002 USER S MANUAL 7 15 Figure 7 9 HI Block Diagram One Port ...
Page 140: ...7 54 DSP96002 USER S MANUAL MOTOROLA ...
Page 166: ...9 10 DSP96002 USER S MANUAL MOTOROLA ...
Page 181: ...MOTOROLA DSP96002 USER S MANUAL 10 15 Figure 10 8 Program Address Bus FIFO ...
Page 337: ...MOTOROLA DSP96002 USER S MANUAL A 149 ...
Page 404: ...A 216 DSP96002 USER S MANUAL MOTOROLA PC xxxx D ...
Page 460: ...A 272 DSP96002 USER S MANUAL MOTOROLA SIOP Not affected ...
Page 484: ...A 296 DSP96002 USER S MANUAL MOTOROLA SSH PC SSL SR SP 1 SP ...
Page 519: ...MOTOROLA DSP96002 USER S MANUAL A 331 ...
Page 718: ...MOTOROLA DSP96002 USER S MANUAL B 199 ...
Page 871: ... MOTOROLA INC 1994 MOTOROLA TECHNICAL DATA SEMICONDUCTOR M Addendum ...
Page 888: ...MOTOROLA INDEX 1 INDEX ...
Page 889: ......