Conference mvblab::alphaserver_4100

515.0. "I2C EEPROM on IIC_Mthrbrd error again!" by KAOFS::D_ORMAECHEA (Denis Ormaechea... Montreal MCS) Fri Feb 28 1997 11:38

	I have two newly installed Alphaserver 4000 rackmounted in two seperate
cabinets who had been showing same problem as addressed in not 222. The customer
does a VMS shutdown of the system then press the HALT switch.He does a show
config and get the following results :

    IIC bus Status (08) error
    
    IIC bus Status (08) error
    
    .... (repeated several times)
    
    IIC bus Status (08) error
    
    IIC bus Status (08) error
    
    IIC bus Status (08) error
    Error: Failed to read I2C EEPROM on iic_mthrbrd
    P00>>>

	Both system did the problem once so far, within a month. I cannot
think of having to replace two brand new backplanes, so i would like to
have somebody to confirm me if that problem has been fixed in any new rev of
the SRM console that is now available on the net. This is the system config.


Thanks in advance !

Denis

******************************************************************************

                           Digital Equipment Corporation
                                 AlphaServer 4000

 Console V3.0-10  OpenVMS PALcode V1.19-2, Digital UNIX PALcode V1.21-14

 Module                          Type     Rev    Name  
 System Motherboard              0        0000   mthrbrd0
 Memory  512 MB EDO              0        0000   mem0     
 CPU (4MB Cache)                 3        0002   cpu0     
 CPU (4MB Cache)                 3        0002   cpu1     
 Bridge (IOD0/IOD1)              600      0032   iod0/iod1
 PCI Motherboard                 8        0003   saddle0  

 Bus 0  iod0 (PCI0)
 Slot   Option Name              Type     Rev    Name
 1      PCEB                     4828086  0005   pceb0    
 2      S3 Trio64/Trio32         88115333 0000   vga0     
 3      DECchip 21140-AA         91011    0012   tulip1   

 Bus 1  pceb0 (EISA Bridge connected to iod0, slot 1)
 Slot   Option Name              Type     Rev    Name

 Bus 0  iod1 (PCI1)
 Slot   Option Name              Type     Rev    Name
 1      NCR 53C810               11000    0002   ncr0     
 2      PCI-PCI Bridge           11011    0002   pcb0     
 3      DECchip 21140-AA         91011    0012   tulip0   
 4      DEC KFPSA                31000    0011   kfpsa0   
 5      DEC KFPSA                31000    0011   kfpsa1   

 Bus 2  pcb0 (PCI-PCI Bridge connected to iod1, slot 2)
 Slot   Option Name              Type     Rev    Name
 0      ISP1020                  10201077 0002   isp0     
P00>>>sho fru
                           Digital Equipment Corporation
                                 AlphaServer 4000

 Console V3.0-10  OpenVMS PALcode V1.19-2, Digital UNIX PALcode V1.21-14

 Module                Part #    Type     Rev    Name      Serial #
 System Motherboard    23803-02  0        0000   mthrbrd0  KA641SEZLT
 Memory  512 MB EDO    N/A       0        0000   mem0      N/A       
 CPU (4MB Cache)       B3004-AA  3        0002   cpu0      KA645SPYRW
 CPU (4MB Cache)       B3004-AA  3        0002   cpu1      KA645SPZDP
 Bridge (IOD0/IOD1)    B3040-AA  600      0032   iod0/iod1 KA635RWZDR
 PCI Motherboard       B3050-AA  8        0003   saddle0   KA640SDMLP

 Bus 0  iod0 (PCI0)
 Slot   Option Name              Type     Rev    Name
 1      PCEB                     4828086  0005   pceb0    
 2      S3 Trio64/Trio32         88115333 0000   vga0     
 3      DECchip 21140-AA         91011    0012   tulip1   

 Bus 1  pceb0 (EISA Bridge connected to iod0, slot 1)
 Slot   Option Name              Type     Rev    Name

 Bus 0  iod1 (PCI1)
 Slot   Option Name              Type     Rev    Name
 1      NCR 53C810               11000    0002   ncr0     
 2      PCI-PCI Bridge           11011    0002   pcb0     
 3      DECchip 21140-AA         91011    0012   tulip0   
 4      DEC KFPSA                31000    0011   kfpsa0   
 5      DEC KFPSA                31000    0011   kfpsa1   

 Bus 2  pcb0 (PCI-PCI Bridge connected to iod1, slot 2)
 Slot   Option Name              Type     Rev    Name
 0      ISP1020                  10201077 0002   isp0     

    Since note 222 was entered, more information has been learned in this
    space. I forgot that the Field had seen this issue (versus only MFG
    during console-based IIC exercising) or I would've updated my reply to 
    note 222 before today.
    
    Specifics: a problem with fast back-to-back reads and/or writes of IIC
    devices was found and fixed in V4.8-xx console.
    
    The 8584 spec has a note which states that you must have at least 6
    clock cycles between parallel-bus accesses when the controller is
    operating between 8 and 12 MHz. We operate the IIC at 10 MHz, so we
    should wait 600ns between accesses. On faster CPUs (400 MHz and
    especially 466 MHz CPUs) we began to see IIC timeouts (as described
    in the base note) on certain systems/boards/configs.
    
    V4.8-xx console fixes this problem by inserting an additional delay
    after every IIC read/write. V4.8-3 and V4.8-5 have been released and
    V4.8-6 will be released in a matter of days. V4.8-5 will ship on the
    V3.9 Alpha FW Update CD (due to FRS any day now). V4.8-6 is being
    released as I speak to work around a 466 MHz CPU SRAM sensitivity
    issue. It will be posted on our FW Web page area in a day or two.
    
    The IIC timing issue exists in all pre-V4.8 versions (V1.0-9, V2.0-3,
    and V3.0-10). The delay in prior console versions was not big enough.

Thanks !


	Very happy to hear this.

Denis