Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS VOLUME 3 REV 2.3, Руководство пользователя, Страница: 627 / 1898

Volume 2, Part 1: Processor Abstraction Layer 2:379
PAL_CACHE_PROT_INFO
Each cache_protection element has the following structure:
• data_bits
–
Unsigned 8-bit integer denoting the number of data bits that each unit
of protection covers. For example, if the cache hardware generates 8 bits of ECC
per 64 bits of data,
data_bits would be 64. This field is only valid if t_d is 0, 2, or 3.
• tagprot_lsb
–
Unsigned 6-bit integer denoting the least-significant tag address bit
that this protection method covers. This field is only valid if t_d is 1, 2, or 3.
• tagprot_msb
–
Unsigned 6-bit integer denoting the most-significant tag address bit
that this protection method covers. This field is only valid if t_d is 1, 2, or 3.
• prot_bits
–
Unsigned 6-bit integer denoting the number of protection bits generated
for the field specified by the t_d element.
• method
–
Unsigned 4-bit integer denoting the protection method, where:
All other values of method are reserved.
• t_d
–
2-bit field denoting whether this protection method applies to the tag, the
data, or both. If over both, the tag and data unit could be concatenated with the
tag either to the left (more significant) or to the right (less significant) than a unit
of data. For the values of 2 and 3, the difference of
tagprot_msb and tagprot_lsb
indicates the number of tag bits that are protected with the data bits. The data bits
are described by the
data_bits field below. This field is encoded as follows:
When obtaining cache information via this call, information for the data cache should be
obtained first, then if the
u bit of the config_info_1 parameter is not set, obtain the
information for the instruction cache.
Figure 11-6. config_info_3 Return Value
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
cache_protection[4]
63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
cache_protection[5]
Figure 11-7. cache_protection Fields
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
t_d method prot_bits tagprot_msb tagprot_lsb data_bits
Table 11-72. method Values
Value Description
0 no ECC or parity protection
1 odd parity protection
2 even parity protection
3 ECC protection
Table 11-73. t_d Values
Value Description
0 Data protection
1 Tag protection
2 Tag+data protection (tag is more significant)
3 Data+tag protection (data is more significant)