Transfer Burst (Tbst); Transfer Burst (Tbst)-Output; Transfer Burst; Transfer Code (Tco-Tc2)-0Utput - IBM PowerPC 604 User Manual

7 .2.4.3 Transfer Burst (TBST)
The transfer burst (TBST) signal is an input/output signal on the 604.
7.2.4.3.1 Transfer Burst (TBST)-Output
Following
are
the state meaning and timing comments for the TBST output signal.
State Meaning Asserted-Indicates that a burst transfer is in progress.
Negated-Indicates that a burst transfer is not in progress. Also,
part
of 1/0 transfer code; see Section 7.2.4.1, "Transfer Type (TTO-
TT4)."
For external control instructions (eciwx and ecowx), TBST is used
~t
bit 28 of the EAR, which is used
to
form the resource ID
(TBSTllTSIZO-TSIZ2).
Timing Comments Assertion/Negation-The same as AO-A31.
High
Impedance-The same as AO-A31.
7 .2.4.3.2 Transfer Burst (TBST)-lnput
Following
are
the state meaning and timing comments for the TBST input signal.
State Meaning Asserted/Negated- For the 1/0 transfer protocol, this signal forms
part
of
the
1/0 transfer code; see Section 7.2.4.1, ''Transfer Type
(TTO-TT4)."
Timing Comments Assertion/Negation-The same as AO-A31.
7 .2.4.4 Transfer Code (TCO-TC2)-0utput
The transfer code (TCO-TC2) consists of three output
signal~
on the 604 that, when
combined with the WT signal, provide additional information about the transaction in
progress. Following
are
the state meaning and timing comments for the TCO-TC2 signals.
State Meaning
Asserted/Negated-Represents a special encoding for the transfer in
progress (see Table 7-3).
Timing Comments Assertion/Negation-The same as AO-A31.
High
Impedance-The same as AO-A31.
Table 7-3. Encodings for TCO-TC2 Signals
Transfer Type
WT'
TCO TC1
T'C2
Transaction
Write-with-klO
1 1 0 0
cache cq>yback
Write-with-kiO
0 1
0 0 Block
invalidate
(debt)
Write-with-kiD 0 0 0 0 Block dean
(dcbst)
Write-with-kill
0 0
1
0
Snoop push
(read operation)
Chapter 7. Signal Descriptions
7-13