89hpes12n3a Integrated Device Technology, 89hpes12n3a Datasheet - Page 4

• Manufacturer Part Number: 89hpes12n3a
• Description: 12-lane, 3-port Pcie I/o Expansion Switch
• Manufacturer: Integrated Device Technology

Pin Description
The active polarity of a signal is defined using a suffix. Signals ending with an “N” are defined as being active, or asserted, when at a logic zero (low)
level. All other signals (including clocks, buses, and select lines) will be interpreted as being active, or asserted, when at a logic one (high) level.
IDT 89HPES12N3A Data Sheet
The following tables list the functions of the pins provided on the PES12N3A. Some of the functions listed may be multiplexed onto the same pin.
Note: In the PES12N3A, the two downstream ports are labeled port 2 and port 4.
SSMBADDR[5,3:1]
PEREFCLKP[2:1]
PEREFCLKN[2:1]
MSMBADDR[4:1]
PE0RP[3:0]
PE0RN[3:0]
PE0TN[3:0]
PE2RP[3:0]
PE2RN[3:0]
PE2TN[3:0]
PE4RP[3:0]
PE4RN[3:0]
PE4TN[3:0]
PE0TP[3:0]
PE2TP[3:0]
PE4TP[3:0]
MSMBCLK
MSMBDAT
REFCLKM
SSMBCLK
SSMBDAT
Signal
Signal
Type
Type
I/O
I/O
I/O
I/O
O
O
O
I
I
I
I
I
I
I
PCI Express Port 0 Serial Data Receive. Differential PCI Express receive
pairs for port 0.
PCI Express Port 0 Serial Data Transmit. Differential PCI Express trans-
mit pairs for port 0.
PCI Express Port 2 Serial Data Receive. Differential PCI Express receive
pairs for port 2.
PCI Express Port 2 Serial Data Transmit. Differential PCI Express trans-
mit pairs for port 2.
PCI Express Port 4 Serial Data Receive. Differential PCI Express receive
pairs for port 4.
PCI Express Port 4 Serial Data Transmit. Differential PCI Express trans-
mit pairs for port 4.
PCI Express Reference Clock. Differential reference clock pair input. This
clock is used as the reference clock by on-chip PLLs to generate the clocks
required for the system logic and on-chip SerDes. The frequency of the dif-
ferential reference clock is determined by the REFCLKM signal.
PCI Express Reference Clock Mode Select. This signal selects the fre-
quency of the reference clock input.
Master SMBus Address. These pins determine the SMBus address of the
serial EEPROM from which configuration information is loaded.
Master SMBus Clock. This bidirectional signal is used to synchronize
transfers on the master SMBus. It is active and generating the clock only
when the EEPROM or I/O Expanders are being accessed.
Master SMBus Data. This bidirectional signal is used for data on the mas-
ter SMBus.
Slave SMBus Address. These pins determine the SMBus address to
which the slave SMBus interface responds.
Slave SMBus Clock. This bidirectional signal is used to synchronize trans-
fers on the slave SMBus.
Slave SMBus Data. This bidirectional signal is used for data on the slave
SMBus.
Table 2 PCI Express Interface Pins
0x0 - 100 MHz
0x1 - 125 MHz
Table 3 SMBus Interface Pins
4 of 31
Name/Description
Name/Description
March 27, 2008