Address Transfer Attribute Signals; Transfer Type Signal (Tt[0Ð4]) Encoding - Motorola MPC8260 PowerQUICC II User Manual

Part III. The Hardware Interface
CLKOUT
ADDR + ATTR
TS
AACK
DBG
TA
Address
Address 1
Tenure
Data Tenure

8.4.3 Address Transfer Attribute Signals

During the address transfer, the address is placed on the address signals, A[0Ð31]. The bus
master provides other signals that characterize the address transferÑtransfer type (TT[0Ð
4]), transfer code (TC[0Ð2]), transfer size (TSIZ[0Ð3]), and transfer burst (TBST) signals.
These signals are discussed in the following sections.
8.4.3.1 Transfer Type Signal (TT[0Ð4]) Encoding
The transfer type signals deÞne the nature of the transfer requested. They indicate whether
the operation is an address-only transaction or whether both address and data are to be
transferred. Table 8-2 describes the MPC8260Õs action as master, slave, and snooper.
60x Bus SpeciÞcation
1
TT[0Ð4]
Command Transaction
00000 Clean block Address
only
00100 Flush block Address
only
8-10
Address 2
Data 1
Figure 8-5. Address Pipelining
Table 8-2. Transfer Type Encoding
2
MPC8260 as Bus Master
Bus Trans. Transaction Source
Address only (if dcbst (if enabled)
enabled)
Address only (if dcbf (if enabled)
enabled)
MPC8260 PowerQUICC II UserÕs Manual
Data 2
MPC8260 as
MPC8260 as Slave
Snooper
Action on Hit Action on Slave Hit
Not applicable AACK asserted;
to MPC8260 MPC8260 takes no
further action.
Not applicable AACK is asserted;
to MPC8260 MPC8260 takes no
further action.
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