21554AA Intel, 21554AA Datasheet - Page 22

• Manufacturer Part Number: 21554AA
• Manufacturer: Intel

Specifications of 21554AA

• Lead Free Status / Rohs Status: Supplier Unconfirmed

Optional Configurations
3.2
Table 3-3.
Table 3-4.
3.3
Table 3-5.
3-2
Central Function and Arbiter Control
Table 3-3
intelligent subsystem is on the local bus, the DE1B55401 can operate using an external arbiter
agent or the 21554 Central Function mode internal arbitration logic.
Central Function and Arbiter Control
Table 3-4
operation.
REQ# and GNT# Selection
a.
Asynchronous Clocking
The local bus can be configured for synchronous or asynchronous operations. If the PICMG slot is
the source of the clocks, the resistor strapping options must be followed as mentioned in
Section
mode and s_clk_o needs to be disabled from the 21554.
operations in more detail.
Synchronous or Asynchronous Clock Control
Switch
Pack
Switch
Pack
J21
J20
Switch
Pack
J20
J20
J21
All switches must be either up or down for correct operation.
3.1. In addition to this, switch bank J20 SW3 needs to indicate asynchronous clocking
specifies how to configure the DE1B55401 as an external or central arbitrator. When an
shows the configuration of switch pack switches for system arbitration with PICMG
Switch
Switch
Switch
SW2
SW3
SW4
SW5
SW1
SW2
SW3
SW4
SW5
SW1
a
Synchronous host and local
clock domains
Disable 21554 s_clk_o
Request/
Grant
req#1
gnt#1
req#2
gnt#2
req#3
gnt#3
Switch
Down
Enable 21554 arbiter
Disable 21554 arbiter
21554 PCI-to-PCI Non-Transparent Bridge Evaluation Board User’s Guide
Switch
Down
Switch Down
System slot (J102) as arbiter
REQ1 from PICMG slot
GNT1 from PICMG slot
REQ2 from PICMG slot
GNT2 from PICMG slot
REQ2 from PICMG slot
GNT2 from PICMG slot
Asynchronous host and
local clock domains
Enable 21554 s_clk_o
Switch
Up
System slot J101 is
the Central Function
System slot J101 is
the external arbiter.
Switch
Up
Table 3-5
Description
Central Function Mode pr_ad<6>
Arbiter Function pr_ad<7>
lists these switches and their
Switch Up
21554 as arbiter
REQ1 from 21554
GNT1 from 21554
REQ2 from 21554
GNT2 from 21554
REQ2 from 21554
GNT2 from 21554
Synchronous/
Asynchronous Operation
pr_ad<4>
s_clk_o
pr_ad<5>
Description