PI7C9X20404SLCFDE Pericom Semiconductor, PI7C9X20404SLCFDE Datasheet - Page 45

• 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: -

7.2.51
7.2.52
July 2009 – Revision 1.2
Pericom Semiconductor
ACKNOWLEDGE LATENCY TIMER – OFFSET B0h
SWITCH OPERATION MODE – OFFSET B4h (Upstream Port)
BIT
29:16
30
31
BIT
0
2:1
3
4
5
6
7
FUNCTION
User ACK Latency
Timer
Enable User ACK
Latency
VGA Capability
Enable
FUNCTION
Store-Forward
Cut-through
Threshold
Port Arbitration
Mode
Credit Update Mode
Ordering on
Different Egress Port
Mode
Ordering on
Different Tag of
Completion Mode
Reserved
TYPE
TYPE
RW
RW
RW
RW
RW
RW
RW
RW
RO
RO
Page 45 of 77
DESCRIPTION
A 14-bit register contains a user-defined value. The default value may be
changed by SMBus or auto-loading from EEPROM.
Reset to 0.
When asserted, the user-defined ACK latency value is be employed. The
default value may be changed by SMBus or auto-loading from EEPROM.
Reset to 0b.
When asserted, the VGA Capability is enabled. The value may be changed by
auto-loading from EEPROM.
Reset to 1b.
DESCRIPTION
When set, a store-forward mode is used. Otherwise, the chip is working under
cut-through mode. The default value may be changed by SMBus or auto-
loading from EEPROM.
Reset to 0b.
Cut-through Threshold. When forwarding a packet from low-speed port to
high-speed mode, the chip provides the capability to adjust the forwarding
threshold. The default value may be changed by SMBus or auto-loading from
EEPROM.
00b: the threshold is set at the middle of forwarding packet
01b: the threshold is set ahead 1-cycle of middle point
10b: the threshold is set ahead 2-cycle of middle point.
11b: the threshold is set ahead 3-cycle of middle point.
Reset to 01b.
When set, the round-robin arbitration will stay in the arbitrated port even if
the credit is not enough but request is pending.
When clear, the round-robin arbitration will always go to the requesting port,
which the outgoing credit is enough for the packet queued in the port.
The default value may be changed by SMBus or auto-loading from
EEPROM.
Reset to 0b.
When set, the frequency of releasing new credit to the link partner will be one
credit per update.
When clear, the frequency of releasing new credit to the link partner will be
two credits per update.
The default value may be changed by SMBus or auto-loading from
EEPROM.
Reset to 0b.
When set, there has ordering rule on packets for different egress port. The
default value may be changed by SMBus or auto-loading from EEPROM.
Reset to 0b.
When set, there has ordering rule between completion packet with different
tag. The default value may be changed by SMBus or auto-loading from
EEPROM.
Reset to 0b.
Reset to 0.
4Port-4Lane PCI Express® Switch
SlimLine
PI7C9X20404SL
Datasheet
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