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Chapter 6: IP Core Interfaces
6–49
Avalon-MM Interface
June 2012
Altera Corporation
Stratix V Hard IP for PCI Express
Table 6–24
lists the interfaces of the Avalon-MM Stratix V Hard IP for PCI Express
with links to the sections that describe them.
f
Variations with Avalon-MM interface implement the Avalon-MM protocol described
in the
Avalon Interface Specifications.
Refer to this specification for information about
the Avalon-MM protocol, including timing diagrams.
32-Bit Non-Bursting Avalon-MM Control Register Access (CRA) Slave
Signals
The optional CRA port for the full-featured IP core allows upstream PCI Express
devices and external Avalon-MM masters to access internal control and status
registers.
Table 6–25
describes the CRA slave signals.
Table 6–24. Signal Groups in the Avalon-MM Stratix V Hard IP for PCI Express Variants
Signal Group
Full
Featured
Completer
Only Single
DWord
Description
Logical
Avalon-MM CRA Slave
v
—
“32-Bit Non-Bursting Avalon-MM Control Register Access (CRA) Slave
Signals” on page 6–49
Avalon-MM RX Master
v
v
“RX Avalon-MM Master Signals” on page 6–50
Avalon-MM TX Slave
v
—
“64-Bit Bursting TX Avalon-MM Slave Signals” on page 6–51
Clock
v
v
Reset and Status
v
v
“Reset Signals and Status Signals” on page 6–28
Physical and Test
Transceiver Control
v
v
“Transceiver Reconfiguration” on page 6–53
Serial
v
v
“Serial Interface Signals” on page 6–54
Pipe
v
v
“PIPE Interface Signals” on page 6–59
Test
v
v
Table 6–25. Avalon-MM CRA Slave Interface Signals (Part 1 of 2)
Signal Name
I/O
Type
Description
cra_irq_irq
O
Irq
Interrupt request. A port request for an Avalon-MM interrupt.
cra_readdata[31:0]
O
Readdata
Read data lines
cra_waitrequest
O
Waitrequest Wait request to hold off more requests
cra_address[11:0]
I
Address
An address space of 16,384 bytes is allocated for the control registers.
Avalon-MM slave addresses provide address resolution down to the
width of the slave data bus. Because all addresses are byte addresses,
this address logically goes down to bit 2. Bits 1 and 0 are 0.
cra_byteenable[3:0]
I
Byteenable
Byte enable
cra_chipselect
I
Chipselect
Chip select signal to this slave
cra_read
I
Read
Read enable