6. Bridging
65
Tsi384 User Manual
May 5, 2014
Integrated Device Technology
www.idt.com
6.5
Forwarding of PCIe to PCI
The Tsi384 forwards posted, non-posted, and upstream read completions to the PCI devices, and stores
the non-posted TLPs’ state information to return the completion TLPs to the PCIe Interface.
6.5.1
PCIe Memory Write Request
The Tsi384 forwards the received PCIe Memory Write Requests to the PCI Interface with either
Memory Write (MW) or Memory Write and Invalidate (MWI) command. The Tsi384 translates the
request into a PCI transaction using the MWI command if it meets the MWI command rules specified
in the
PCI Local Bus Specification (Revision 3.0)
, and the MWI bit is set in the
. An MW command is used for the remaining part of the MWI transaction if the transaction is
disconnected such that the remaining request does not meet the MWI command rules. The Tsi384 does
not support relaxed ordering among the received requests. It forwards all requests in the order they are
received even if the relaxed ordering bit is set for some of the requests.
6.5.2
PCIe Non-posted Requests
The Tsi384 translates the PCIe Memory Read Requests into PCI transactions that use a PCI memory
read command (that is, Memory Read, Memory Read Line, or Memory Read Multiple) based on its
cacheline size value, requested byte enables, and prefetchable and non-prefetchable memory windows.
PCIe Read Request command translation is completed as follows:
•
Memory Read if the PCIe Request falls into the non-prefetchable address range defined by the
“PCI Memory Base and Limit Register”
•
Memory Read Line if the PCIe Request falls into the prefetchable range defined by the
, and the requested data size is less than or equal to the value specified in
Cacheline Size of the
“PCI Miscellaneous 0 Register”
.
•
Memory Read Multiple if the PCIe Request falls into the prefetchable range defined by the
, and the requested the data size is greater than or equal to the value
specified in Cacheline Size of the
“PCI Miscellaneous 0 Register”
.
The Tsi384 attempts another outstanding request if the current request is retried or disconnected to
improve the link bandwidth utilization. It does not attempt to read beyond the requested length. The
Tsi384 decomposes the requests if the requested data length is greater than 128 bytes, and returns the
completions in 128-byte boundary fragments.
The Tsi384 uses PCI byte enable fields such that the byte enable information is preserved and no
additional bytes are requested for the transactions that fall into the non-prefetchable address range (for
example, Configuration, I/O, and Memory read commands).
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 ...