6. Bridging
68
Tsi384 User Manual
May 5, 2014
Integrated Device Technology
www.idt.com
6.8
Forwarding of PCI-X to PCIe
The Tsi384 forwards Memory Write, Memory Write Block, Memory Read DWORD, Memory Read
Block, alias to Memory Read Block, I/O requests, and downstream read completions, to the
PCIe Interface as per PCIe constraints and protocol mapping requirements specified in section 2.5 of
the
PCI Express Base Specification (Revision 1.1)
. The device terminates all non-posted requests on
the PCI-X Interface a with split response and then forwards them onto the PCIe Interface. Once the
completion is returned for the forwarded request, the Tsi384 provides data for reads and status for the
writes to the requester through split completion and split completion message transactions,
respectively. The device initiates split completions on the PCI-X Interface on ADB boundaries if the
requested data size is greater than one ADB. However, byte counts larger than 128 bytes can be
returned to the PCI-X bus provided the data is available in the buffer. The Tsi384 provides normal
completion up to the device boundary, and split completion error message with master abort for the
remaining length, if the received PCI-X read byte count is in out of range.
The Tsi384 discards the enqueued split request if the requested data is not returned before the
completion timeout expires (see
) and returns a split completion error
message with master abort to the requester.
6.9
Split Completion Buffer
The Tsi384 ensures sufficient buffer space is available to handle all the requested data before initiating
a read request on the PCI-X or PCIe Interface. It decomposes the received read request while
forwarding onto the destination interface if the request’s read data size is greater than the available
buffer size. As a result, the Tsi384 never sets the Split Completion Overrun bit in the
. The Tsi384 decomposes the read requests received from the PCI-X Interface into two
or more requests on the PCIe Interface if one of the following conditions is met:
•
Starting address plus requested length crosses the 4-KB address boundary
•
Requested length exceeds the MAX_RD_SIZE in
“PCIe Device Control and Status Register”
•
Requested length exceeds the available buffer space
Содержание TSI384
Страница 1: ... IDT Tsi384 PCIe to PCI Bridge User Manual May 5 2014 ...
Страница 10: ...Contents 10 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 36: ...2 Signal Descriptions 36 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 56: ...4 Addressing 56 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 62: ...5 Configuration Transactions 62 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 74: ...6 Bridging 74 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 78: ...7 PCI X Arbitration 78 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 128: ...11 Power Management 128 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 136: ...12 Serial EEPROM 136 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 142: ...13 JTAG 142 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 268: ...16 Packaging 268 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 276: ...276 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 280: ...Index 280 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...