Changes between Version 40 and Version 41 of InterconnexionNetworks


Ignore:
Timestamp:
Mar 18, 2013, 3:51:43 PM (11 years ago)
Author:
alain
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • InterconnexionNetworks

    v40 v41  
    6262=== 3.1  VCI encoding of the various transaction types on the direct network ===
    6363
    64 There are 5 transaction types ('''READ''', '''WRITE''', '''LL''', '''SC''', '''CAS''') on the direct network, and four sub-types for '''READ''' transactions. These types are encoded through the pair of VCI fields '''CMD''' and '''PKTID'''. When a given initiator can send several simultaneous transactions of a given type (such as several simultaneous '''WRITE''' transactions), the VCI '''TRDID''' field is used to discriminate them.
    65 
    66 Possible values for the VCI '''CMD''' field are :
    67 
    68 || encoding (2 bits) || value                    ||
    69 ||                   ||                          ||
    70 || 00                || CMD_NOP / CMD_STORE_COND ||
    71 || 01                || CMD_READ                 ||
    72 || 10                || CMD_WRITE                ||
    73 || 11                || CMD_LOCKED_READ          ||
    74 
    75 The '''PKTID''' field in TSAR is 4 bits long. Only 8 types of transaction are used : the MSB is ignored (reserved for future use). A specific VCI '''CMD''' value must be used for each '''PKTID''' value, as described in the table below :
    76 
    77 || encoding (4 bits) || '''PKTID''' value   || '''CMD''' value ||
    78 ||                   ||                     ||                 ||
    79 || X000              || TYPE_READ_DATA_UNC  || CMD_READ        ||
    80 || X001              || TYPE_READ_DATA_MISS || CMD_READ        ||
    81 || X010              || TYPE_READ_INS_UNC   || CMD_READ        ||
    82 || X011              || TYPE_READ_INS_MISS  || CMD_READ        ||
    83 || X100              || TYPE_WRITE          || CMD_WRITE       ||
    84 || X101              || TYPE_CAS            || CMD_NOP         ||
    85 || X110              || TYPE_LL             || CMD_LOCKED_READ ||
    86 || X111              || TYPE_SC             || CMD_STORE_COND  ||
     64There are 8 transaction types ('''READ_DATA_UNC''', '''READ_DATA_MISS''', '''READ_INS_UNC''', '''READ_INS_MISS''', '''WRITE''', '''CAS''', '''LL''', '''SC''') on the direct network. These types are encoded through the pair of VCI fields '''CMD''' and '''PKTID'''. The '''PKTID''' field in TSAR is 4 bits long, but the MSB is ignored (reserved for future use).
     65
     66||TYPE          ||CMD (2 bits)||PKTID (4 bits)|| '''PKTID''' mnemo   || '''CMD''' mnemo ||
     67||              ||            ||              ||                     ||                 ||
     68||READ_DATA_UNC ||01          ||X000          || TYPE_READ_DATA_UNC  || CMD_READ        ||
     69||READ_DATA_MISS||01          ||X001          || TYPE_READ_DATA_MISS || CMD_READ        ||
     70||READ_INS_UNC  ||01          ||X010          || TYPE_READ_INS_UNC   || CMD_READ        ||
     71||READ_INS_MISS ||01          ||X011          || TYPE_READ_INS_MISS  || CMD_READ        ||
     72||WRITE         ||10          ||X100          || TYPE_WRITE          || CMD_WRITE       ||
     73||CAS           ||00          ||X101          || TYPE_CAS            || CMD_STORE_COND  ||
     74||LL            ||11          ||X110          || TYPE_LL             || CMD_LOCKED_READ ||
     75||SC            ||00          ||X111          || TYPE_SC             || CMD_STORE_COND  ||
    8776
    8877Remarks on the '''PKTID''' field encoding :
     
    9079 * for a TYPE_READ, bit 1 is set (resp. not set) for an instruction (resp. data) request
    9180 * bit 2 can be used to check for a TYPE_READ (bit 2 = 0)
     81
     82When a given initiator can send several simultaneous transactions of a given type (such as several simultaneous '''WRITE''' transactions), the VCI '''TRDID''' field is used to discriminate them.
    9283
    9384==== 3.1.1 VCI READ transaction ====