Bit
Field
Description
Effect on
Software
Available
5
ITCM0_RE
Recoverable (1-bit) ECC error in
ITCM0
None
ITCM0
present
6
ITCM0_UE
Unrecoverable (2-bit) ECC error in ITCM0
Possibly fatal
ITCM0 present
7
ITCM1_RE
Recoverable (1-bit) ECC error in ITCM1
None
ITCM1 present
8
ITCM1_UE
Unrecoverable (2-bit) ECC error in ITCM1
Likely fatal
ITCM1 present
9
ITCM2_RE
Recoverable (1-bit) ECC error in ITCM2
None
ITCM2 present
10
ITCM2_UE
Unrecoverable (2-bit) ECC error in ITCM2
Likely fatal
ITCM2 present
11
ITCM3_RE
Recoverable (1-bit) ECC error in ITCM3
None
ITCM3 present
12
ITCM3_UE
Unrecoverable (2-bit) ECC error in ITCM3
Likely fatal
ITCM3 present
13
DCTAG_RE
Recoverable (1-bit) ECC error in data cache tag RAM
None
Data cache
present
14
DCTAG_UE
Unrecoverable (2-bit) ECC error in data cache tag RAM
Likely fatal
Data cache
present
15
DCDAT_RE
Recoverable (1-bit with dirty line, 2-bit or 3-bit with clean line) ECC
error in data cache data RAM. Excludes recoverable errors found during
writeback of a dirty line.
None
Data cache
present
16
DCDAT_UE
Unrecoverable (2-bit with dirty line) ECC error in data cache data RAM.
Excludes unrecoverable errors found during writeback of a dirty line.
Likely fatal
Data cache
present
17
DCWB_RE
Recoverable (1-bit) ECC error in data cache data RAM or victim line
buffer RAM during writeback of a dirty line.
None
Data cache
present
18
DCWB_UE
Unrecoverable (2-bit) ECC error in data cache data RAM or victim line
buffer RAM during writeback of a dirty line.
Likely fatal
Data cache
present
19
TLB_RE
Recoverable (1 bit) ECC error in TLB RAM (hardware read of TLB)
None
MMU present
20
TLB_UE
Unrecoverable (2 bit) ECC error in TLB RAM (hardware read of TLB)
Possibly fatal
MMU present
21
TLB_SW
Software-triggered (1, 2, or 3 bit) ECC error in software read of TLB
Possibly fatal
MMU present
22
DTCM0_RE
Recoverable (1-bit) ECC error in DTCM0
None
DTCM0 present
23
DTCM0_UE
Unrecoverable (2-bit) ECC error in DTCM0
Likely fatal
DTCM0 present
24
DTCM1_RE
Recoverable (1-bit) ECC error in DTCM1
None
DTCM1 present
25
DTCM1_UE
Unrecoverable (2-bit) ECC error in DTCM1
Likely fatal
DTCM1 present
26
DTCM2_RE
Recoverable (1-bit) ECC error in DTCM2
None
DTCM2 present
27
DTCM2_UE
Unrecoverable (2-bit) ECC error in DTCM2
Likely fatal
DTCM2 present
28
DTCM3_RE
Recoverable (1-bit) ECC error in DTCM3
None
DTCM3 present
29
DTCM3_UE
Unrecoverable (2-bit) ECC error in DTCM3
Likely fatal
DTCM3 present
5.2.11. JTAG Debug Module
The Nios II/f core supports the JTAG debug module to provide a JTAG interface to
software debugging tools. The Nios II/f core supports an optional enhanced interface
that allows real-time trace data to be routed out of the processor and stored in an
external debug probe.
Note:
The Nios II MMU does not support the JTAG debug module trace.
5. Nios II Core Implementation Details
NII-PRG | 2018.04.18
Nios II Processor Reference Guide
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