3. Data Path
39
Tsi384 User Manual
May 5, 2014
Integrated Device Technology
www.idt.com
Figure 7: Downstream Data Path
3.2
Transaction Management
The following sub-sections describe how the Tsi384 handles upstream and downstream transactions.
3.2.1
Upstream Transaction Management
Transactions that originate on the PCI/X Interface that are destined for the PCIe Interface are stored in
the respective queues or buffers in the PCI/X clock domain, and are then forwarded to the PCIe Core
(see
). PCI/X buffer logic decomposes the received transactions as per the PCIe constraints
(for example, MAX_RD_SIZE, MAX_PAY_SIZE, RCB, and 4-KB address boundary). Three sets of
data and control signals for the three types of transactions (posted, non-posted, and completions) are
used between the PCI/X and PCIe Cores.
Transactions are stored temporarily in the PCIe Core buffers before they are used to construct TLPs,
and are then made visible to TLP arbiter. The TLPs are processed by the TLP arbiter only after
ordering rules are satisfied. The TLP arbiter selects one of the five input TLPs (error message, PME
message, posted, completion, and non-posted TLPs) in a round-robin mode if sufficient credits and
retry buffer space is available for the specific TLPs. The TLP arbiter continues to check the available
credit and retry buffer space against each of the active inputs, and selects the one that meets the
constraint. The ECRC adder calculates and appends a 32-bit ECRC value to the end of the TLP
selected by the arbiter if ECRC generation is enabled by software, and then forwards the TLP to the
Data link layer.
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PCI Core
Receive Flow
Con trol Buf fers
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Device Core I nterface
S plit Co mp le tio n
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 ...