Changes between Version 63 and Version 64 of library_stdio


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Timestamp:
Apr 11, 2015, 10:57:52 PM (10 years ago)
Author:
alain
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  • library_stdio

    v63 v64  
    4545 ==  __Coprocessors related system calls__ ==
    4646
    47 The GIET_VM allows user applications to use hardware accelerators (called coprocessors). These coprocessors can be distributed in the architecture, but there is at most one coprocessor per cluster, identified by the cluster (x,y) coordinares. To be supported by the GIET_VM, a coprocessor must use the ''vci_mwmr_dma'' component, that is a multi-channels DMA controller.
     47The GIET_VM allows user applications to use hardware accelerators (called coprocessors). These coprocessors can be distributed in the architecture, but there is at most one coprocessor per cluster. To be supported by the GIET_VM, a coprocessor must use the ''vci_mwmr_dma'' component, that is a generic multi-channels DMA controller.
    4848
    4949On the coprocessor side, it provides TO_COPROC or FROM_COPROC ports, that implement FIFO interfaces. Coprocessor can request to transfer one or several bursts of 32 bits words on a TO_COPROC or FROM_COPROC port, without address. The burst size (generally a cache line), the number of TO_COPROC and FROM_COPROC ports, and the number of bursts for a given port are hardware parameters. Each port define a private communication channel between the coprocessor and a user memory buffer. The total number of channels cannot be larger than 16. A channel is identified by an index, and the TO_COPROC channels have the smallest indexes.
     
    5656'''WARNING''' : For all channels, the memory buffer address and size  must be multiple of the hardware burst size.
    5757
    58 Several channels can simultaneously run in different modes. The VCI transactions corresponding to different channels are interleaved and parallelized on the VCI network.
     58The VCI transactions corresponding to different channels are interleaved and parallelized on the VCI network.
    5959
    6060Besides these communication channels, the ''vci_mwmr_dma'' component support up to 16 coprocessor-specific configurarion/status registers. The ''configuration'' registers are Read and Write. The ''status'' registers are Read only.
    6161
    6262
    63 The list of supported coprocessors and their characteristics are defined below:
     63The list of currently  supported coprocessors and their characteristics are defined below:
    6464||  coproc_type               ||     Function                             ||nb_to_coproc || nb_from_coproc || nb_config  || nb_status || 
    6565|| COPROC_TYPE_GCD ||   Greater Common Divider      ||    2                 ||          1               ||       1         ||       0        ||
     
    6767|| COPROC_TYPE_CPY  ||   Memory Copy                      ||    1                 ||          1               ||        1        ||       0        ||     
    6868
    69  === 1) void '''giet_coproc_alloc'''( unsigned int   coproc_type,  unsigned int*  info,  unsigned int*  cluster_xy ) ===
     69 === 1) void '''giet_coproc_alloc'''( unsigned int   coproc_type,  unsigned int*  coproc_key,  unsigned int* coproc_info ) ===
    7070This function allocates a private coprocessor to the calling task, taking a lock to grant exclusive ownership.
    7171In the current implementation, the task exit if there is no coprocessor of requested type in the same cluster as the calling task.
    7272In case of success, it returns the coprocessor characteristics in the '''coproc_info''' and '''cluster_xy''' variables.
    7373 * '''coproc_type''' : see supported types above
    74  * '''coproc_info''' :  nb_to_coprocs = info[7:0] / nb_from_coproc = info[15:8] / nb_config = info[23:16] / nb_status = info[31:24]
    75  * '''cluster_xy''' : cluster coordinates
    76 
    77  === 2) void '''giet_coproc_release'''( unsigned int   cluster_xy ) ===
     74 * '''coproc_key''' (return value) : identifier for coprocessor access
     75 * '''coproc_info''' (return value) :  nb_to_coprocs = info[7:0] / nb_from_coproc = info[15:8] / nb_config = info[23:16] / nb_status = info[31:24]
     76
     77
     78 === 2) void '''giet_coproc_release'''( unsigned int  coproc_key ) ===
    7879 This function releases the coprocessor allocated to the calling task.
    7980 * '''cluster_xy''' cluster coordinates
     
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