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50 lines
1.2 KiB
50 lines
1.2 KiB
6 years ago
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import gex
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class SPI(gex.Unit):
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"""
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SPI master direct access
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"""
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def _type(self):
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return 'SPI'
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def query(self, slave:int, tbytes, rlen:int, rskip:int=-1):
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"""
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Query a slave.
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If rskip is -1 (default), the tbytes length will be used.
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Set it to 0 to skip nothing.
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"""
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if rskip == -1:
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rskip = len(tbytes)
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pb = gex.PayloadBuilder()
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pb.u8(slave)
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pb.u16(rskip)
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pb.u16(rlen)
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pb.blob(tbytes)
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if rlen > 0:
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resp = self._query(0, pb.close())
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return resp.data
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else:
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# write only
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self._query(0x80, pb.close())
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return []
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def write(self, slave:int, tbytes):
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"""
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Write with no response received
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"""
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self.query(slave, tbytes, rlen=0, rskip=0)
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def multicast(self, slaves:int, tbytes):
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"""
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Write with multiple slaves at once.
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Slaves is a right-aligned bitmap (eg. pins 0,2,3 would be 0b1101)
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"""
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pb = gex.PayloadBuilder()
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pb.u16(slaves)
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pb.blob(tbytes)
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# write only
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self._query(0x81, pb.close())
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