PI7C9X20404SLCFDE Pericom Semiconductor, PI7C9X20404SLCFDE Datasheet - Page 16

• Manufacturer Part Number: PI7C9X20404SLCFDE
• Description: IC PCIE PACKET SWITCH 128LQFP
• Manufacturer: Pericom Semiconductor
• Series: SlimLine™r

Specifications of PI7C9X20404SLCFDE

• Applications: Data Transport
• Interface: Advanced Configuration Power Interface (ACPI)
• Package / Case: 128-LQFP
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -

5
Multiple virtual PCI-to-PCI Bridges (VPPB), connected by a virtual PCI bus, reside in the Switch. Each VPPB
contains the complete PCIe architecture layers that consist of the physical, data link, and transaction layer. The
packets entering the Switch via one of VPPBs are first converted from serial bit-stream into parallel bus signals in
physical layer, stripped off the link-related header by data link layer, and then relayed up to the transaction layer to
extract out the transaction header. According to the address or ID embedded in the transaction header, the entire
transaction packets are forwarded to the destination VPPB for formatting as a serial-type PCIe packet through the
transmit circuits in the data link layer and physical layer. The following sections describe these function elements
for processing PCIe packets within the Switch.
5.1
The physical layer circuit design is based on the PHY Interface for PCI Express Architecture (PIPE). It contains
Physical Media Attachment (PMA) and Physical Coding Sub-layer (PCS) blocks. PMA includes Serializer/
Deserializer (SERDES), PLL
idle detector, and input/output buffers. PCS consists of framer, 8B/10B encoder/decoder, receiver elastic buffer, and
PIPE PHY control/status circuitries. To provide the flexibility for port configuration, each lane has its own control
and status signals for MAC to access individually. In addition, a pair of PRBS generator and checker is included for
PHY built-in self test. The main functions of physical layer circuits include the conversion between serial-link and
parallel bus, provision of clock source for the Switch, resolving clock difference in receiver end, and detection of
physical layer errors.
In order to meet the different application needs, the driving current and equalization of each transmitting channels
can be adjusted using EEPROM individually. The driver current of each channel is set to 20mA in default mode. To
change the current value, the user can program the EEPROM for nominal value (HIDRV, LODRV) or actual value
(DTX [3:0]), which is a scaled multiple of Inom. The following tables illustrate the possible transmitted current
values the chip provides.
1
July 2009 – Revision 1.2
Pericom Semiconductor
Multiple lanes could share the PLL.
FUNCTIONAL DESCRIPTION
Table 5-1 Nominal Driver Current Values (Inom)
Table 5-2 Ratio of Actual Current and Nominal Current
PHYSICAL LAYER CIRCUIT
DTX [3:0]
HIDRV
0000
0001
0010
0011
0100
0101
0110
0
0
1
1
1
, Clock Recovery module, receiver detection circuits, beacon transmitter, electrical
ACTUAL CURRENT / NOMINAL CURRENT
LODRV
0
1
0
1
Page 16 of 77
NOMINAL DRIVER CURENT
1.00
1.05
1.10
1.15
1.20
1.25
1.30
Reserved
20 mA
10 mA
28 mA
4Port-4Lane PCI Express® Switch
SlimLine
PI7C9X20404SL
Datasheet
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