GR740-UM-DS, Nov 2017, Version 1.7
74
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GR740
6.10.6 Cache control register
The cache control register located at ASI 0x2, offset 0, contains control and status registers for the I
and D cache.
Table 55.
ASI 0x2, 0x00 - CCR - Cache control register
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
R
S
T
E
R PS
TB
DS FD FI
FT
R ST R
IP DP
ITE
IDE
DTE
DDE
DF IF
DCS
ICS
0 NR 0
0
0x0
0
0
0
0b01
0
1
0
0
0
0
0
0
0
0
0
0
0
r
rw
r
rw
rw
rw rw rw
r
r
r
r
r
r
rw
rw
rw
rw
rw rw
rw
rw
31
Reserved
30
Snoop Tag Flag (STE) - Set when parity error is detected in the data physical (snoop) tags.
29
Reserved
28
Parity Select (PS) - if set diagnostic read will return 4 check bits in the lsb bits, otherwise tag or data
word is returned.
27: 24
Test Bits (TB) - if set, check bits will be xored with test bits TB during diagnostic write.
23
Data cache snoop enable (DS) - if set, will enable data cache snooping.
22
Flush data cache (FD). If set, will flush the instruction cache. Always reads as zero.
21
Flush Instruction cache (FI). If set, will flush the instruction cache. Always reads as zero.
20: 19
FT scheme (FT) - “01” = 4-bit checking implemented
18
Reserved for future implementations
17
Separate snoop tags (ST). Has value 1.
16
Reserved
15
Instruction cache flush pending (IP). This bit is set when an instruction cache flush operation is in
progress
14
Data cache flush pending (DP). This bit is set when an data cache flush operation is in progress.
13: 12
Instruction Tag Errors (ITE) - Number of detected parity errors in the instruction tag cache.
11: 10
Instruction Data Errors (IDE) - Number of detected parity errors in the instruction data cache.
9: 8
Data Tag Errors (DTE) - Number of detected parity errors in the data tag cache.
7:6
Data Data Errors (DDE) - Number of detected parity errors in the data data cache.
5
Data Cache Freeze on Interrupt (DF) - If set, the data cache will automatically be frozen when an
asynchronous interrupt is taken.
4
Instruction Cache Freeze on Interrupt (IF) - If set, the instruction cache will automatically be frozen
when an asynchronous interrupt is taken.
3:2
Data Cache state (DCS) - Indicates the current data cache state according to the following: X0= dis-
abled, 01 = frozen, 11 = enabled.
1:0
Instruction Cache state (ICS) - Indicates the current data cache state according to the following: X0=
disabled, 01 = frozen, 11 = enabled.