User`s guide

The XMI
2.5.8 Tag Bad Data Transactions
The Tag Bad Data (TBDATA) transaction (see Figure 2–19) is a write used
in place of a DWMASK transaction to mark bad a cache location that
has supplied corrupted data. Since the XMI processors support ECC for
cache data transfers, it takes a double-bit error to require the use of a
TBDATA transaction. System software associates the bad data with an
actual process by marking the corrupt location as bad, since the first read
reference to this location will fail.
The XMI supports quadword, octaword, and hexword TBDATA
transactions.
Figure 2–19 Tag Bad Data Command
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0
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9
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90
WRITE MASK ADDRESS<29:0>
LENGTH 00 = Hexword
10 = Quadword
11 = Octaword
msb−p192−89
1011 MBZ
ADDRESS<39:30>
TAG BAD DATA COMMAND
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