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@ -1,4 +1,4 @@
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.\" $NetBSD: ahc.4,v 1.32 2009/04/10 15:05:06 joerg Exp $
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.\" $NetBSD: ahc.4,v 1.33 2009/05/04 19:45:51 wiz Exp $
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.\"
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.\" Copyright (c) 1995, 1996, 1997, 1998, 2000
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.\" Justin T. Gibbs. All rights reserved.
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@ -162,7 +162,8 @@ with this option enabled.
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.\" Individual controllers may be configured to operate in the target role
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.\" through the
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.\" .Dq Dv AHC_TMODE_ENABLE
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.\" configuration option. The value assigned to this option should be a bitmap
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.\" configuration option.
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.\" The value assigned to this option should be a bitmap
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.\" of all units where target mode is desired.
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.\" For example, a value of 0x25, would enable target mode on units 0, 2, and 5.
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.\" .Pp
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@ -202,7 +203,8 @@ but care should be taken when using a 284x
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.Pq Tn VESA No local bus controller
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in an
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.Tn EISA
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system. The jumpers setting the I/O area for the 284x should match the
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system.
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The jumpers setting the I/O area for the 284x should match the
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.Tn EISA
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slot into which the card is inserted to prevent conflicts with other
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.Tn EISA
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@ -212,9 +214,10 @@ Performance and feature sets vary throughout the aic7xxx product line.
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The following table provides a comparison of the different chips supported
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by the
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.Nm
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driver. Note that wide and twin channel features, although always supported
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by a particular chip, may be disabled in a particular motherboard or card
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design.
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driver.
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Note that wide and twin channel features, although always supported
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by a particular chip, may be disabled in a particular motherboard
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or card design.
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.Pp
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.Bl -column "aic7895c" "MIPS" "EISA/VL" "MaxSync" "MaxWidth" "SCBs" "2 3 4 5 6 7 8"
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.It Sy Chip Ta Sy MIPS Ta Sy Bus Ta Sy MaxSync Ta Sy MaxWidth Ta Sy SCBs Ta Sy Features
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@ -394,11 +397,14 @@ host adapter chips.
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.Sh SCSI CONTROL BLOCKS (SCBs)
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Every transaction sent to a device on the SCSI bus is assigned a
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.Sq SCSI Control Block
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(SCB). The SCB contains all of the information required by the
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controller to process a transaction. The chip feature table lists
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the number of SCBs that can be stored in on-chip memory. All chips
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with model numbers greater than or equal to 7870 allow for the on chip
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SCB space to be augmented with external SRAM up to a maximum of 255 SCBs.
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(SCB).
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The SCB contains all of the information required by the controller
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to process a transaction.
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The chip feature table lists the number of SCBs that can be stored
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in on-chip memory.
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All chips with model numbers greater than or equal to 7870 allow
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for the on chip SCB space to be augmented with external SRAM up to
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a maximum of 255 SCBs.
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Very few Adaptec controller configurations have external SRAM.
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.Pp
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If external SRAM is not available, SCBs are a limited resource.
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@ -408,20 +414,23 @@ To fully use the SCSI bus and the devices on it,
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requires much more concurrency.
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The solution to this problem is
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.Em SCB Paging ,
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a concept similar to memory paging. SCB paging takes advantage of
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the fact that devices usually disconnect from the SCSI bus for long
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periods of time without talking to the controller. The SCBs
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for disconnected transactions are only of use to the controller
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when the transfer is resumed. When the host queues another transaction
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for the controller to execute, the controller firmware will use a
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free SCB if one is available. Otherwise, the state of the most recently
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disconnected (and therefor most likely to stay disconnected) SCB is
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saved, via DMA, to host memory, and the local SCB reused to start
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the new transaction. This allows the controller to queue up to
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255 transactions regardless of the amount of SCB space. Since the
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local SCB space serves as a cache for disconnected transactions, the
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more SCB space available, the less host bus traffic consumed saving
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and restoring SCB data.
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a concept similar to memory paging.
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SCB paging takes advantage of the fact that devices usually disconnect
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from the SCSI bus for long periods of time without talking to the
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controller.
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The SCBs for disconnected transactions are only of use to the
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controller when the transfer is resumed.
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When the host queues another transaction for the controller to
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execute, the controller firmware will use a free SCB if one is
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available.
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Otherwise, the state of the most recently disconnected (and therefor
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most likely to stay disconnected) SCB is saved, via DMA, to host
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memory, and the local SCB reused to start the new transaction.
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This allows the controller to queue up to
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255 transactions regardless of the amount of SCB space.
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Since the local SCB space serves as a cache for disconnected
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transactions, the more SCB space available, the less host bus
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traffic consumed saving and restoring SCB data.
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.Sh SEE ALSO
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.Xr aha 4 ,
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.Xr ahb 4 ,
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@ -456,23 +465,26 @@ Some
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.Tn Quantum
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drives (at least the Empire 2100 and 1080s) will not run on an
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.Tn AIC7870
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Rev B in synchronous mode at 10MHz. Controllers with this problem have a
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42 MHz clock crystal on them and run slightly above 10MHz. This confuses
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the drive and hangs the bus. Setting a maximum synchronous negotiation rate
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of 8MHz in the
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Rev B in synchronous mode at 10MHz.
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Controllers with this problem have a
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42 MHz clock crystal on them and run slightly above 10MHz.
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This confuses the drive and hangs the bus.
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Setting a maximum synchronous negotiation rate of 8MHz in the
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.Tn SCSI-Select
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utility will allow normal operation.
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.Pp
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.\" Although the Ultra2 and Ultra160 products have sufficient instruction
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.\" ram space to support both the initiator and target roles concurrently,
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.\" this configuration is disabled in favor of allowing the target role
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.\" to respond on multiple target ids. A method for configuring dual
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.\" to respond on multiple target ids.
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.\" A method for configuring dual
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.\" role mode should be provided.
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.\" .Pp
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.\" Tagged Queuing is not supported in target mode.
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.\" .Pp
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.\" Reselection in target mode fails to function correctly on all high
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.\" voltage differential boards as shipped by Adaptec. Information on
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.\" voltage differential boards as shipped by Adaptec.
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.\" Information on
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.\" how to modify HVD board to work correctly in target mode is available
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.\" from Adaptec.
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Target mode is not supported on
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@ -1,4 +1,4 @@
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.\" $NetBSD: ftp.1,v 1.128 2009/03/12 12:35:17 joerg Exp $
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.\" $NetBSD: ftp.1,v 1.129 2009/05/04 19:47:09 wiz Exp $
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.\"
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.\" Copyright (c) 1996-2008 The NetBSD Foundation, Inc.
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.\" All rights reserved.
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@ -486,7 +486,8 @@ Toggle the use of the extended
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.Dv EPSV
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and
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.Dv EPRT
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commands on all IP, IPv4, and IPv6 connections respectively. First try
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commands on all IP, IPv4, and IPv6 connections respectively.
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First try
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.Dv EPSV /
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.Dv EPRT ,
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and then
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