80KSBR200 Datasheet, PDF(19/172 Page) Integrated Device Technology

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80KSBR200 Datasheet, PDF (19/172 Pages) Integrated Device Technology – sRIO SERIAL BUFFER FLOW-CONTROL DEVICE

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IDT 80KSBR200

Notes

Advanced Datasheet*

â The Ftype, which defines the type of packet being sent. The types are shown in section 3.4.4.

â The Target Address, a.k.a Destination ID. This will be 8 bits or 16 bits, depending upon the state of TT.

â The Source Address, a.k.a Source ID. This will be 8 bits or 16 bits, depending upon the state of TT.

â The Transaction, which is dependent upon the packet Ftype. The supported transactions are described

individually.

3.4.1 sRIO Physical Layer Header

The sRIO physical layer header is shown in Figure 14. The various fields are defined in the sRIO Physical Layer 1x/4x

specification. The sRIO priority is the priority of the packet during transmission. The contents of the physical layer do not

go beyond the interface, except the packet priority (Pri) may be dictated for any transmitted packet. In the SerB, there are

two methods for setting the priority.

â If a transmitted packet is a response to a received packet, the sRIO response priority will be one priority level

higher than the priority of the request packet, up to the maximum priority.

â If the transmitted packet is being initiated by the SerB, the priority of the packet will be dictated by the SerB. In

most cases, the priority will be dictated by the "Case Scenario".

ACKID

Rsrv =

Pri

Figure 4 sRIO Physical Layer Header

3.4.2 sRIO Physical Layer CRC

CRC-16 accompanies all sRIO packets and is defined in the sRIO Physical Layer 1x/4x specification. The location of

CRC within the packet is shown in Figure 3.

3.4.3 sRIO Transport Layer Header (8/16 bit Device IDs)

During sRIO "bring up", the SerB shall support both 8 and 16 bit device ID fields. Once configured as either 8 or 16 bit,

the SerB does not support the other type and will drop packets once configured.

Considering that the only packet type supported is the type configured, the TT bits within the packet are not useful. The

SerB insures that the proper TT bits are included in every packet sent. Incoming packet TT bits are a "don't care".

Within the sRIO packet, the TT (transaction type) is used to identify the size of the fields as shown in Figure 5.

Definition

8-Bit Device ID Fields

16-Bit Device ID Fields

Reserved

Figure 5 Transaction Types (8 or 16)

The source and destination IDs in the sRIO packet will be either 8 or 16 bit as configured. Every sRIO packet that the

SerB generates contains a Target ID that has been generated from one of following ways:

â The packet is in response to a request. The Target ID is the source ID of the requestor.

â The packet is generated by the SerB through a "case scenario". The Target ID is included in the case

scenario.

â Any packet that is generated by a case scenario will use the Source ID of the queue to send the packet.

â Any flag associated with a queue will use the Source ID of the queue to send the doorbell.

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March 19, 2007

â2005 Integrated Device Technology, Inc. All rights reserved. Advanced Datasheet for informational purposes only. Product specifications subject to change without notice.NOT AN OFFER FOR SALE The information presented herein is subject to a

Non-Disclosure Agreement (NDA) and is for planning purposes only. Nothing contained in this presentation, whether verbal or written, is intended as, or shall have the effect of, a sale or an offer for sale that creates a contractual power of acceptance.

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