FlashDevice.py revision 10801:049eb85e8ea2 
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36# Authors: Rene de Jong
37#
38
39from m5.params import *
40from m5.proxy import *
41from AbstractNVM import *
42
43#Distribution of the data.
44#sequential: sequential (address n+1 is likely to be on the same plane as n)
45#Random: @TODO Not yet implemented
46#stripe: striping over all the planes
47class DataDistribution(Enum): vals = ['sequential', 'stripe']
48
49class FlashDevice(AbstractNVM):
50    type = 'FlashDevice'
51    cxx_header = "dev/arm/flash_device.hh"
52    # default blocksize is 128 kB.This seems to be the most common size in
53    # mobile devices (not the image blocksize)
54    blk_size = Param.MemorySize("128kB", "Size of one disk block")
55    # disk page size is 2 kB. This is the most commonly used page size in
56    # flash devices
57    page_size = Param.MemorySize("2kB", "Size of one disk page")
58    # There are many GC flavours. It is impossible to cover them all; this
59    # parameter enables the approximation of different GC algorithms
60    GC_active = Param.Percent(50, "Percentage of the time (in whole numbers) \
61        that the GC is activated if a block is full")
62    # Access latencies. Different devices will have different latencies, but
63    # the latencies will be around the default values.
64    read_lat = Param.Latency("25us", "Read Latency")
65    write_lat = Param.Latency("200us", "Write Latency")
66    erase_lat = Param.Latency("1500us", "Erase Delay")
67    # Number of planes ought to be a power of two according to ONFI standard
68    num_planes = Param.UInt32(1, "Number of planes per die")
69    # Data distribution. Default is none. It is adviced to switch to stripe
70    # when more than one plane is used.
71    data_distribution = Param.DataDistribution('sequential', "Distribution \
72        of the data in the adress table; Stripe needed for multiple\
73        planes; otherwise use: sequential")
74
75