8 of 40 October 3, 2011
IDT 89HPES32H8 Data Sheet
Signal Type Name/Description
CCLKDS I Common Clock Downstream. When the CCLKDS pin is asserted, it indicates that a
common clock is being used between the downstream device and the downstream
port.
CCLKUS I Common Clock Upstream. When the CCLKUS pin is asserted, it indicates that a
common clock is being used between the upstream device and the upstream port.
MSMBSMODE I Master SMBus Slow Mode. The assertion of this pin indicates that the master SMBus
should operate at 100 KHz instead of 400 KHz. This value may not be overridden.
P01MERGEN I Port 0 and 1 Merge. P01MERGEN is an active low signal. It is pulled low internally via
a 251K ohm resistor.
When this pin is low, port 0 is merged with port 1 to form a single x8 port. The Serdes
lanes associated with port 1 become lanes 4 through 7 of port 0. When this pin is
high, port 0 and port 1 are not merged, and each operates as a single x4 port
P23MERGEN I Port 2 and 3 Merge. P23MERGEN is an active low signal. It is pulled low internally via
a 251K ohm resistor.
When this pin is low, port 2 is merged with port 3 to form a single x8 port. The Serdes
lanes associated with port 3 become lanes 4 through 7 of port 2. When this pin is
high, port 2 and port 3 are not merged, and each operates as a single x4 port.
P45MERGEN I Port 4 and 5 Merge. P45MERGEN is an active low signal. It is pulled low internally via
a 251K ohm resistor.
When this pin is low, port 4 is merged with port 5 to form a single x8 port. The Serdes
lanes associated with port 5 become lanes 4 through 7 of port 4. When this pin is
high, port 4 and port 5 are not merged, and each operates as a single x4 port.
P67MERGEN I Port 6 and 7 Merge. P67MERGEN is an active low signal. It is pulled low internally via
a 251K ohm resistor.
When this pin is low, port 6 is merged with port 7 to form a single x8 port. The Serdes
lanes associated with port 7 become lanes 4 through 7 of port 6. When this pin is
high, port 6 and port 7 are not merged, and each operates as a single x4 port.
PERSTN I Fundamental Reset. Assertion of this signal resets all logic inside the PES32H8 and
initiates a PCI Express fundamental reset.
RSTHALT I Reset Halt. When this signal is asserted during a PCI Express fundamental reset, the
PES32H8 executes the reset procedure and remains in a reset state with the Master
and Slave SMBuses active. This allows software to read and write registers internal to
the device before normal device operation begins. The device exits the reset state
when the RSTHALT bit is cleared in the PA_SWCTL register by an SMBus master.
SWMODE[3:0] I Switch Mode. These configuration pins determine the PES32H8 switch operating
mode. These pins should be static and not change following the negation of PERSTN.
0x0 - Normal switch mode
0x1 - Normal switch mode with Serial EEPROM initialization
0x2 through 0x7 - Reserved
0x8 - Normal switch mode with upstream port failover (port 0 selected as the
upstream port)
0x9 - Normal switch mode with upstream port failover (port 2 selected as the
upstream port)
0xA - Normal switch mode with Serial EEPROM initialization and upstream port
failover (port 0 selected as the upstream port)
0xB - Normal switch mode with Serial EEPROM initialization and upstream port
failover (port 2 selected as the upstream port)
0xC through 0xF - Reserved
Table 5 System Pins