4-39
BUS PROTOCOL
Read Line transactions are issued to the bus at full speed. TRDY# is not asserted because the
transactions are reads and the snoop results indicate no implicit writeback data transfers.
The response and data transfers for transaction 1 occur in T7, the clock after the snoop results
are sampled. The data is transferred in 4 consecutive clocks.
DBSY# is asserted for transaction 1 in T7 and remains asserted until T10, the clock before the
last data transfer. A special optimization can be made because the same agent drives both data
transfers. Since the response agent knows that DBSY# will be deasserted in T10 and it owns the
next data transfer, it can drive the next response and data transfer in T11, one clock after DBSY#
deassertion.
Note that no waitstates are inserted by the single addressed/responding agent. The back end of
the bus will eventually throttle the front end in this scenario, but full bus bandwidth is attainable.
4.6.2.7.
FULL SPEED WRITE PARTIAL TRANSACTIONS
Figure 4-24 shows the steady-state behavior of the bus with full speed Write Partial
Transactions.
Figure 4-23. Full Speed Read Line Transactions
CLK
ADS#
2
1
4
3
8
7
6
5
{REQUEST}
DBSY#
D[63:0]#
DRDY#
HIT#
TRDY#
RS[2:0]#
10
9
12
11
16
15
14
13
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1
1
1
1
2
2
2
2
1
2
3
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5
6
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3
3
1
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6
1
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1
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3
Summary of Contents for Pentium Pro Family
Page 17: ...1 Component Introduction ...
Page 26: ...2 Pentium Pro Processor Architecture Overview ...
Page 27: ......
Page 36: ...3 Bus Overview ...
Page 62: ...4 Bus Protocol ...
Page 105: ...5 Bus Transactions and Operations ...
Page 126: ...6 Range Registers ...
Page 131: ...7 Cache Protocol ...
Page 135: ...8 Data Integrity ...
Page 148: ...9 Configuration ...
Page 161: ...10 Pentium Pro Processor Test Access Port TAP ...
Page 172: ...11 Electrical Specifications ...
Page 201: ...12 GTL Interface Specification ...
Page 229: ...13 3 3V Tolerant Signal Quality Specifications ...
Page 233: ...14 Thermal Specifications ...
Page 239: ...15 Mechanical Specifications ...
Page 241: ...15 2 MECHANICAL SPECIFICATIONS s Figure 15 1 Package Dimensions Bottom View ...
Page 252: ...16 Tools ...
Page 260: ...16 8 TOOLS Figure 16 4 Generic MP System Layout for Debug Port Connection ...
Page 264: ...17 OverDrive Processor Socket Specification ...
Page 290: ...A Signals Reference ...
Page 320: ...Index ...
Page 328: ......