ncr53c8xx.txt

linux 内核源代码

  error occurs.

Field B : DSTAT io register (DMA STATUS)
  Bit 0x40 : MDPE Master Data Parity Error
             Data parity error detected on the PCI BUS.
  Bit 0x20 : BF   Bus Fault
             PCI bus fault condition detected
  Bit 0x01 : IID  Illegal Instruction Detected
             Set by the chip when it detects an Illegal Instruction format 
             on some condition that makes an instruction illegal.
  Bit 0x80 : DFE Dma Fifo Empty
             Pure status bit that does not indicate an error.
  If the reported DSTAT value contains a combination of MDPE (0x40), 
  BF (0x20), then the cause may be likely due to a PCI BUS problem.

Field C : SIST io register (SCSI Interrupt Status)
  Bit 0x08 : SGE  SCSI GROSS ERROR
             Indicates that the chip detected a severe error condition 
             on the SCSI BUS that prevents the SCSI protocol from functioning
             properly.
  Bit 0x04 : UDC  Unexpected Disconnection
             Indicates that the device released the SCSI BUS when the chip 
             was not expecting this to happen. A device may behave so to 
             indicate the SCSI initiator that an error condition not reportable              using the SCSI protocol has occurred.
  Bit 0x02 : RST  SCSI BUS Reset
             Generally SCSI targets do not reset the SCSI BUS, although any 
             device on the BUS can reset it at any time.
  Bit 0x01 : PAR  Parity
             SCSI parity error detected.
  On a faulty SCSI BUS, any error condition among SGE (0x08), UDC (0x04) and 
  PAR (0x01) may be detected by the chip. If your SCSI system sometimes 
  encounters such error conditions, especially SCSI GROSS ERROR, then a SCSI 
  BUS problem is likely the cause of these errors.

For fields D,E,F,G and H, you may look into the sym53c8xx_defs.h file 
that contains some minimal comments on IO register bits.
Field D : SOCL  Scsi Output Control Latch
          This register reflects the state of the SCSI control lines the 
          chip want to drive or compare against.
Field E : SBCL  Scsi Bus Control Lines
          Actual value of control lines on the SCSI BUS.
Field F : SBDL  Scsi Bus Data Lines
          Actual value of data lines on the SCSI BUS.
Field G : SXFER  SCSI Transfer
          Contains the setting of the Synchronous Period for output and 
          the current Synchronous offset (offset 0 means asynchronous).
Field H : SCNTL3 Scsi Control Register 3
          Contains the setting of timing values for both asynchronous and 
          synchronous data transfers. 

Understanding Fields I, J, K and dumps requires to have good knowledge of 
SCSI standards, chip cores functionnals and internal driver data structures.
You are not required to decode and understand them, unless you want to help 
maintain the driver code.

16. Synchronous transfer negotiation tables

Tables below have been created by calling the routine the driver uses
for synchronisation negotiation timing calculation and chip setting.
The first table corresponds to Ultra chips 53875 and 53C860 with 80 MHz 
clock and 5 clock divisors.
The second one has been calculated by setting the scsi clock to 40 Mhz 
and using 4 clock divisors and so applies to all NCR53C8XX chips in fast 
SCSI-2 mode.

Periods are in nano-seconds and speeds are in Mega-transfers per second.
1 Mega-transfers/second means 1 MB/s with 8 bits SCSI and 2 MB/s with 
Wide16 SCSI.

16.1 Synchronous timings for 53C895, 53C875 and 53C860 SCSI controllers

 ----------------------------------------------
 Negotiated                     NCR settings
 Factor   Period   Speed        Period   Speed
 ------   ------   ------       ------   ------
 10       25       40.000       25       40.000   (53C895 only)
 11       30.2     33.112       31.25    32.000   (53C895 only)
 12       50       20.000       50       20.000
 13       52       19.230       62       16.000
 14       56       17.857       62       16.000
 15       60       16.666       62       16.000
 16       64       15.625       75       13.333
 17       68       14.705       75       13.333
 18       72       13.888       75       13.333
 19       76       13.157       87       11.428
 20       80       12.500       87       11.428
 21       84       11.904       87       11.428
 22       88       11.363       93       10.666
 23       92       10.869       93       10.666
 24       96       10.416      100       10.000
 25      100       10.000      100       10.000
 26      104        9.615      112        8.888
 27      108        9.259      112        8.888
 28      112        8.928      112        8.888
 29      116        8.620      125        8.000
 30      120        8.333      125        8.000
 31      124        8.064      125        8.000
 32      128        7.812      131        7.619
 33      132        7.575      150        6.666
 34      136        7.352      150        6.666
 35      140        7.142      150        6.666
 36      144        6.944      150        6.666
 37      148        6.756      150        6.666
 38      152        6.578      175        5.714
 39      156        6.410      175        5.714
 40      160        6.250      175        5.714
 41      164        6.097      175        5.714
 42      168        5.952      175        5.714
 43      172        5.813      175        5.714
 44      176        5.681      187        5.333
 45      180        5.555      187        5.333
 46      184        5.434      187        5.333
 47      188        5.319      200        5.000
 48      192        5.208      200        5.000
 49      196        5.102      200        5.000


16.2 Synchronous timings for fast SCSI-2 53C8XX controllers

 ----------------------------------------------
 Negotiated                     NCR settings
 Factor   Period   Speed        Period   Speed
 ------   ------   ------       ------   ------
 25      100       10.000      100       10.000
 26      104        9.615      125        8.000
 27      108        9.259      125        8.000
 28      112        8.928      125        8.000
 29      116        8.620      125        8.000
 30      120        8.333      125        8.000
 31      124        8.064      125        8.000
 32      128        7.812      131        7.619
 33      132        7.575      150        6.666
 34      136        7.352      150        6.666
 35      140        7.142      150        6.666
 36      144        6.944      150        6.666
 37      148        6.756      150        6.666
 38      152        6.578      175        5.714
 39      156        6.410      175        5.714
 40      160        6.250      175        5.714
 41      164        6.097      175        5.714
 42      168        5.952      175        5.714
 43      172        5.813      175        5.714
 44      176        5.681      187        5.333
 45      180        5.555      187        5.333
 46      184        5.434      187        5.333
 47      188        5.319      200        5.000
 48      192        5.208      200        5.000
 49      196        5.102      200        5.000


17. Serial NVRAM (added by Richard Waltham: [e-mail])

17.1 Features

Enabling serial NVRAM support enables detection of the serial NVRAM included
on Symbios and some Symbios compatible host adaptors, and Tekram boards. The 
serial NVRAM is used by Symbios and Tekram to hold set up parameters for the 
host adaptor and it's attached drives.

The Symbios NVRAM also holds data on the boot order of host adaptors in a
system with more than one host adaptor. This enables the order of scanning
the cards for drives to be changed from the default used during host adaptor
detection.

This can be done to a limited extent at the moment using "reverse probe" but
this only changes the order of detection of different types of cards. The
NVRAM boot order settings can do this as well as change the order the same
types of cards are scanned in, something "reverse probe" cannot do.

Tekram boards using Symbios chips, DC390W/F/U, which have NVRAM are detected
and this is used to distinguish between Symbios compatible and Tekram host 
adaptors. This is used to disable the Symbios compatible "diff" setting
incorrectly set on Tekram boards if the CONFIG_SCSI_53C8XX_SYMBIOS_COMPAT 
configuration parameter is set enabling both Symbios and Tekram boards to be 
used together with the Symbios cards using all their features, including
"diff" support. ("led pin" support for Symbios compatible cards can remain
enabled when using Tekram cards. It does nothing useful for Tekram host
adaptors but does not cause problems either.)


17.2 Symbios NVRAM layout

typical data at NVRAM address 0x100 (53c810a NVRAM)
-----------------------------------------------------------
00 00
64 01
8e 0b

00 30 00 00 00 00 07 00 00 00 00 00 00 00 07 04 10 04 00 00 

04 00 0f 00 00 10 00 50 00 00 01 00 00 62 
04 00 03 00 00 10 00 58 00 00 01 00 00 63 
04 00 01 00 00 10 00 48 00 00 01 00 00 61 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 

0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 

0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 

00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 

00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 

00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 

fe fe
00 00
00 00
-----------------------------------------------------------
NVRAM layout details

NVRAM Address 0x000-0x0ff not used
              0x100-0x26f initialised data
              0x270-0x7ff not used

general layout

        header  -   6 bytes,
        data    - 356 bytes (checksum is byte sum of this data)
        trailer -   6 bytes
                  ---
        total     368 bytes

data area layout

        controller set up  -  20 bytes
        boot configuration -  56 bytes (4x14 bytes)
        device set up      - 128 bytes (16x8 bytes)
        unused (spare?)    - 152 bytes (19x8 bytes)
                             ---
        total                356 bytes

-----------------------------------------------------------
header

00 00   - ?? start marker
64 01   - byte count (lsb/msb excludes header/trailer)
8e 0b   - checksum (lsb/msb excludes header/trailer)
-----------------------------------------------------------
controller set up

00 30 00 00 00 00 07 00 00 00 00 00 00 00 07 04 10 04 00 00
                   |     |           |     |
                   |     |           |      -- host ID
                   |     |           |
                   |     |            --Removable Media Support
                   |     |               0x00 = none
                   |     |               0x01 = Bootable Device
                   |     |               0x02 = All with Media
                   |     |
                   |      --flag bits 2
                   |        0x00000001= scan order hi->low
                   |            (default 0x00 - scan low->hi)
                    --flag bits 1
                       0x00000001 scam enable
                       0x00000010 parity enable
                       0x00000100 verbose boot msgs

remaining bytes unknown - they do not appear to change in my
current set up for any of the controllers.

default set up is identical for 53c810a and 53c875 NVRAM
(Removable Media added Symbios BIOS version 4.09)
-----------------------------------------------------------
boot configuration

boot order set by order of the devices in this table

04 00 0f 00 00 10 00 50 00 00 01 00 00 62 -- 1st controller
04 00 03 00 00 10 00 58 00 00 01 00 00 63    2nd controller
04 00 01 00 00 10 00 48 00 00 01 00 00 61    3rd controller
00 00 00 00 00 00 00 00 00 00 00 00 00 00    4th controller
       |  |  |  |     |        |     |  |
       |  |  |  |     |        |      ---- PCI io port adr
       |  |  |  |     |         --0x01 init/scan at boot time
       |  |  |  |      --PCI device/function number (0xdddddfff)
       |  |   ----- ?? PCI vendor ID (lsb/msb)
        ----PCI device ID (lsb/msb)

?? use of this data is a guess but seems reasonable

remaining bytes unknown - they do not appear to change in my
current set up

default set up is identical for 53c810a and 53c875 NVRAM
-----------------------------------------------------------
device set up (up to 16 devices - includes controller)

0f 00 08 08 64 00 0a 00 - id 0
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 
0f 00 08 08 64 00 0a 00 

0f 0