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3–24 User Guide Version 11.1 Altera Corporation

PCI Compiler October 2011

PCI Bus Signals

Master Local-Side Signals

Table 3–9 summarizes the pci_mt64 and pci_mt32 master interface

signals that provide the interface between the PCI MegaCore function

and the local-side peripheral device(s) during master transactions.

1 When a local side transaction is not in progress, local side inputs

should be deasserted.

Table 3–9. PCI Master Signals Interfacing to the Local Side (Part 1 of 2)

Name Type Polarity Description

lm_req32n

Input Low Local master request 32-bit data transaction. The local side asserts

this signal to request ownership of the PCI bus for a 32-bit master

transaction. To request a master transaction, it is sufficient for the

local-side device to assert

lm_req32n for one clock cycle. When

requesting a 32-bit transaction, only

l_adi[31..0] for a master

write transaction or

l_dato[31..0] for a master read

transaction is valid.

The local side cannot request the bus until the current master

transaction has completed. After being granted mastership of the

PCI bus, the

lm_req32n signal should be asserted only after

lm_tsr[3] is deasserted.

lm_req64n

Input Low Local master request 64-bit data transaction. The local side asserts

this signal to request ownership of the PCI bus for a 64-bit master

transaction. To request a master transaction, it is sufficient for the

local side device to assert

lm_req64n for one clock cycle. When

requesting a 64-bit data transaction,

pci_mt64 requests a 64-bit

PCI transaction. When the target does not assert its

ack64n

signal, the transaction will be 32 bits. In a 64-bit master write

transaction where the target does not assert its

ack64n signal,

pci_mt64 automatically accepts 64-bit data on the local side and

multiplexes the data appropriately to 32 bits on the PCI side. When

the local side requests 64-bit PCI transactions, it must ensure that

the address is at a

QWORD boundary. This signal is not implemented

pci_mt32.

The local side cannot request the bus until the current master

transaction has completed. After being granted mastership of the

PCI bus, the

lm_req64n signal should be asserted only after

lm_tsr[3] is deasserted.

lm_lastn

Input Low Local master last. This signal is driven by the local side to request

that the

pci_mt64 or pci_mt32 master interface ends the

current transaction. When the local side asserts this signal, the PCI

MegaCore function master interface deasserts

framen as soon as

possible and asserts

irdyn to indicate that the last data phase has

begun. The local side must assert this signal for one clock cycle to

initiate the end of the current master transaction.

1 2 ... 93 94 95 96 97 98 99 100 101 102 103 ... 359 360

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