2. Bus Operation
40
Tsi310 User Manual
80B6020_MA001_05
2.4.2
Type 1 to Type 0 Translation by Bridge
Type 1 configuration transactions are used to configure devices in a hierarchical bus structure
having one or more bridges. A bridge is the only type of device that should respond to a Type 1
configuration transaction. Type 1configuration commands are used to access PCI/PCI-X devices
that are located on a bus segment other than the one where the Type 1 transaction is initiated.
The Tsi310 performs a Type 1 to Type 0 translation when a Type 1 transaction is presented on
the primary interface that is destined for a device attached directly to the secondary interface. In
this case, the bridge must convert the configuration transaction to a Type 0 format so that the
secondary bus device can accept it. Type 1 to Type 0 translations are never performed in the
upstream direction.
The Tsi310 claims a Type 1 configuration transaction on its primary bus and translates it into a
Type 0 transaction on the secondary bus when the following conditions are met during the
address phase:
•
P_C/BE(3:0)# command indicates a configuration read or configuration write transaction
•
P_AD(1:0) are b‘01’
•
The bus number on P_AD(23:16) is the same as the value in the secondary bus number
register in the bridge’s configuration space
When the Tsi310 translates the Type 1 transaction to a Type 0 transaction on the secondary
interface, it performs the following translations to the address:
•
Sets S_AD(1:0) to b‘00’
•
Decodes the device number specified and drives the bit pattern specified in
on
S_AD(31:16) for use in the assertion of the device’s IDSEL signal
•
Sets S_AD(15:11) to b‘00000’ if the secondary bus is operating in conventional PCI mode
(in the PCI-X mode, the device number is passed through unchanged)
•
Leaves the function number and register number fields unchanged
The Tsi310 asserts a unique address signal based on the device number. These address signals
may be used as secondary bus IDSEL signals. Mapping of the address signals depends on the
device number on P_AD(15:11) of the Type1 configuration transaction.
indicates how the bridge decodes the device number field. This default mapping may be
modified by the secondary bus private device mask register (see
.
Содержание Tsi310TM
Страница 8: ...Contents 8 Tsi310 User Manual 80B6020_MA001_05...
Страница 10: ...List of Figures 10 Tsi310 User Manual 80B6020_MA001_05...
Страница 12: ...List of Tables 12 Tsi310 User Manual 80B6020_MA001_05...
Страница 18: ...18 Tsi310 User Manual 80B6020_MA001_05...
Страница 44: ...2 Bus Operation 44 Tsi310 User Manual 80B6020_MA001_05...
Страница 58: ...3 Clocking and Reset Options 58 Tsi310 User Manual 80B6020_MA001_05...
Страница 62: ...4 Transaction Ordering 62 Tsi310 User Manual 80B6020_MA001_05...
Страница 150: ...5 Configuration Registers 150 Tsi310 User Manual 80B6020_MA001_05...
Страница 170: ...6 Signals and Pinout 170 Tsi310 User Manual 80B6020_MA001_05...
Страница 190: ...7 JTAG Boundary Scan 190 Tsi310 User Manual 80B6020_MA001_05...
Страница 196: ...8 Electrical Characteristics 196 Tsi310 User Manual 80B6020_MA001_05...
Страница 200: ...9 Package Information 200 Tsi310 User Manual 80B6020_MA001_05...
Страница 202: ...A Ordering Information 202 Tsi310 User Manual 80B6020_MA001_05...
Страница 206: ...Index 206 Tsi310 User Manual 80B6020_MA001_05...