spcm_tools.py

from ctypes import *

# load registers for easier access
from py_header.regs import *

#
# **************************************************************************
# szTypeToName: doing name translation
# **************************************************************************
#
def szTypeToName (lCardType):
    sName = ''
    lVersion = (lCardType & TYP_VERSIONMASK)
    if (lCardType & TYP_SERIESMASK) == TYP_M2ISERIES:
        sName = 'M2i.%04x'%lVersion
    elif (lCardType & TYP_SERIESMASK) == TYP_M2IEXPSERIES:
        sName = 'M2i.%04x-Exp'%lVersion
    elif (lCardType & TYP_SERIESMASK) == TYP_M3ISERIES:
        sName = 'M3i.%04x'%lVersion
    elif (lCardType & TYP_SERIESMASK) == TYP_M3IEXPSERIES:
        sName = 'M3i.%04x-Exp'%lVersion
    elif (lCardType & TYP_SERIESMASK) == TYP_M4IEXPSERIES:
        sName = 'M4i.%04x-x8'%lVersion
    elif (lCardType & TYP_SERIESMASK) == TYP_M4XEXPSERIES:
        sName = 'M4x.%04x-x4'%lVersion
    elif (lCardType & TYP_SERIESMASK) == TYP_M2PEXPSERIES:
        sName = 'M2p.%04x-x4'%lVersion
    else:
        sName = 'unknown type'
    return sName



#
# **************************************************************************
# pvAllocMemPageAligned: creates a buffer for DMA that's page-aligned 
# **************************************************************************
#
def pvAllocMemPageAligned (qwBytes):
    dwAlignment = 4096
    dwMask = dwAlignment - 1

    # allocate non-aligned, slightly larger buffer
    qwRequiredNonAlignedBytes = qwBytes * sizeof (c_char) + dwMask
    pvNonAlignedBuf = (c_char * qwRequiredNonAlignedBytes)()

    # get offset of next aligned address in non-aligned buffer
    misalignment = addressof (pvNonAlignedBuf) & dwMask
    if misalignment:
        dwOffset = dwAlignment - misalignment
    else:
        dwOffset = 0
    return (c_char * qwBytes).from_buffer (pvNonAlignedBuf, dwOffset)