Motorola MPC8260 - Manual (Page 242)

8-10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA
Part III. The Hardware Interface
Figure 8-5. Address Pipelining
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.
Table 8-2. Transfer Type Encoding
TT[0Ð4] 1
60x Bus SpeciÞcation 2 MPC8260 as Bus Master
MPC8260 as
Snooper
MPC8260 as Slave
Command Transaction Bus Trans. Transaction Source Action on Hit Action on Slave Hit
00000 Clean block Address
only Address only (if
enabled) dcbst (if enabled) Not applicable
to MPC8260 AACK asserted;
MPC8260 takes no
further action.
00100 Flush block Address
only Address only (if
enabled) dcbf (if enabled) Not applicable
to MPC8260 AACK is asserted;
MPC8260 takes no
further action.
CLKOUT
ADDR + ATTR
TS
AACK
DBG
TA
Address
Data Tenure
Tenure Address 1
Data 1
Address 2
Data 2