參數(shù)資料
型號: PI7C8150A-33
英文描述: PCI Bridge | 2-Port PCI-to-PCI Bridge
中文描述: PCI橋| 2端口PCI至PCI橋
文件頁數(shù): 69/115頁
文件大小: 879K
代理商: PI7C8150A-33
PI7C8150B
2-PORT PCI-TO-PCI BRIDGE
ADVANCE INFORMATION
Page 69 of 115
July 31, 2003 – Revision 1.031
When PI7C8150B receives a target abort or a master abort in response to a locked delayed
transaction, PI7C8150B returns a target abort or a master abort when the initiator repeats
the locked transaction. The initiator must then de-assert LOCK_L at the end of the
transaction. PI7C8150B sets the appropriate status bits, flagging the abnormal target
termination condition (see Section 3.8). Normal forwarding of unlocked posted and
delayed transactions is resumed.
When PI7C8150B receives a target abort or a master abort in response to a locked posted
write transaction, PI7C8150B cannot pass back that status to the initiator. PI7C8150B
asserts SERR_L on the initiator bus when a target abort or a master abort is received during
a locked posted write transaction, if the SERR_L enable bit is set in the command register.
Signal SERR_L is asserted for the master abort condition if the master abort mode bit is set
in the bridge control register (see Section 6.4).
8
PCI BUS ARBITRATION
PI7C8150B must arbitrate for use of the primary bus when forwarding upstream
transactions. Also, it must arbitrate for use of the secondary bus when forwarding
downstream transactions. The arbiter for the primary bus resides external to PI7C8150B,
typically on the motherboard. For the secondary PCI bus, PI7C8150B implements an
internal arbiter. This arbiter can be disabled, and an external arbiter can be used instead.
This chapter describes primary and secondary bus arbitration.
8.1
PRIMARY PCI BUS ARBITRATION
PI7C8150B implements a request output pin, P_REQ_L, and a grant input pin, P_GNT_L,
for primary PCI bus arbitration. PI7C8150B asserts P_REQ_L when forwarding
transactions upstream; that is, it acts as initiator on the primary PCI bus. As long as at least
one pending transaction resides in the queues in the upstream direction, either posted write
data or delayed transaction requests, PI7C8150B keeps P_REQ_L asserted. However, if a
target retry, target disconnect, or a target abort is received in response to a transaction
initiated by PI7C8150B on the primary PCI bus, PI7C8150B de-asserts P_REQ_L for two
PCI clock cycles.
For all cycles through the bridge, P_REQ_L is not asserted until the transaction request has
been completely queued. When P_GNT_L is asserted LOW by the primary bus arbiter
after PI7C8150B has asserted P_REQ_L, PI7C8150B initiates a transaction on the primary
bus during the next PCI clock cycle. When P_GNT_L is asserted to PI7C8150B when
P_REQ_L is not asserted, PI7C8150B parks P_AD, P_CBE, and P_PAR by driving them
to valid logic levels. When the primary bus is parked at PI7C8150B and PI7C8150B has a
transaction to initiate on the primary bus, PI7C8150B starts the transaction if P_GNT_L
was asserted during the previous cycle.
8.2
SECONDARY PCI BUS ARBITRATION
PI7C8150B implements an internal secondary PCI bus arbiter. This arbiter supports eight
external masters on the secondary bus in addition to PI7C8150B. The internal arbiter can
be disabled, and an external arbiter can be used instead for secondary bus arbitration.
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PI7C8150AMA 制造商:Pericom Semiconductor Corporation 功能描述:PCI to PCI Bridge 208-Pin FQFP
PI7C8150AMA-33 制造商:Pericom Semiconductor Corporation 功能描述:PCI-to-PCI Bridge 208-Pin FQFP
PI7C8150AMAE 功能描述:外圍驅(qū)動器與原件 - PCI 2 Port PCI Bridge RoHS:否 制造商:PLX Technology 工作電源電壓: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:FCBGA-1156 封裝:Tray
PI7C8150AMAE-33 功能描述:外圍驅(qū)動器與原件 - PCI 2 Port PCI Bridge RoHS:否 制造商:PLX Technology 工作電源電壓: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:FCBGA-1156 封裝:Tray
PI7C8150AND 制造商:PERICOM 制造商全稱:Pericom Semiconductor Corporation 功能描述:2-PORT PCI-to-PCI BRIDGE