3. Data Path > Overview
22
PEB383 User Manual
July 25, 2011
Integrated Device Technology, Inc.
Confidential - NDA Required
Figure 7: Upstream Data Path[update for PEB383]
3.1.2
Downstream Data Path
In the downstream path, the PEB383 uses one-stage buffering for each type of transaction (see
). These buffers support the store and forward method, receive flow control, protocol
differences, synchronization, and error handling requirements.
S
c
ra
m
b
le
r
Posted FIFO
( 512 bytes)
Non Posted FIFO
4 Entr ies
Completion F IF O
(64 bytes)
Retry Bu ffer (1 KB)
Error Message TLP
EHU
CSR
PME_n
M
a
s
te
r I
n
te
rfa
c
e
T
a
rg
e
t
In
te
rfa
c
e
Posted Buffer (512 bytes)
Non Posted Queue
8 Entr ies
Downstream Read
Completion Buffer
(512 byte s)
PMC
PME
Mesaage
TLP
Posted Request
Non-Posted
Request
Com pletions
Claim
Cycle
Address
Decoder
2
nd
Stage Bufferi ng
Cut through
1
s t
Stage Buffering
Store and Forward
PCIe Core
PCI Core
Device Core
Interface