cxd3220r Sony Electronics, cxd3220r Datasheet - Page 60

• Manufacturer Part Number: cxd3220r
• Description: Ieee1394 Link/transaction Layer Controller Lsi For Sbp-2
• Manufacturer: Sony Electronics

Request Speed
8-2-2-1. Bus Request
In order to access Fair or Priority, waits at least one clock after the CXD3220R becomes idle to send the
request. When the CTL pin is in received state (CTL [0:1] = 10), the CXD3220R interprets the request as being
refused. It is reissued one clock after the next idle state.
In the Cycle Master node, the cycle start message is sent using Priority request. In order to request sending of
Isochronous data, the CXD3220R can issue request after receiving cycle start. Phy clears the Isochronous
request only after the bus is acquired successfully.
The CXD3220R must issue ImmReq while it is receiving a packet addressed to itself in order to send
Acknowledge. When packet reception is completed, Phy immediately acquires the bus and gives authorization
to the CXD3220R. However, if the header CRC is erroneous, the CXD3220R immediately releases the bus.
The CXD3220R can not use this authorization to send other packets. In order to ensure this operation, the
CXD3220R must wait 160ns after completion of packet reception when Phy uses a bus for transmitting
Acknowledge. Then it releases the bus and continues with another request.
Request Type
LREQ [1:3]
LREQ [4:5]
110, 111
000
001
010
011
100
101
00
01
10
11
ImmReq
IsoReq
PriReq
FairReq
RdReq
WrReq
Reserved
Data Rate
100Mb/s
200Mb/s
400Mb/s
Reserved
Name
Immediate bus acquisition request.
To output Ack for an Asynchronous packet reception, immediate bus
acquisition is requested without Arbitration when Idle is detected.
Used to transmit Acknowledge.
Isochronous request. Requests execution of Arbitration.
Used for Isochronous transmit.
Priority request.
Requests execution of Arbitration after Subaction Gap, ignoring Fair protocol.
Used for Cycle Master request.
Fair request.
Requests execution of Arbitration after Subaction Gap according to fair protocol.
Used for Fair transmit.
Read request.
Requests return of register contents according to Status Transfer.
Write request.
Requests write to specified address.
Reserved.
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Description of Activity
CXD3220R