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Revision 3377, 1.1 kB
(checked in by frodo, 9 years ago)
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Much new documentation. Could somebody please check the ten-bit-addr
part?
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- Property svn:eol-style set to
native
- Property svn:keywords set to
Author Date Id Revision
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The I2C protocol knows about two kinds of device addresses: normal 7 bit |
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addresses, and an extended set of 10 bit addresses. The sets of addresses |
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do not intersect: the 7 bit address 0x10 is not the same as the 10 bit |
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address 0x10 (though a single device could respond to both of them). You |
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select a 10 bit address by adding an extra byte after the address |
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byte: |
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S Addr7 Rd/Wr .... |
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becomes |
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S 11110 Addr10 Rd/Wr |
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S is the start bit, Rd/Wr the read/write bit, and if you count the number |
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of bits, you will see the there are 8 after the S bit for 7 bit addresses, |
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and 16 after the S bit for 10 bit addresses. |
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WARNING! The current 10 bit address support is EXPERIMENTAL. There are |
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several places in the code that will cause SEVERE PROBLEMS with 10 bit |
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addresses, even though there is some basic handling and hooks. Also, |
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almost no supported adapter handles the 10 bit addresses correctly. |
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As soon as a real 10 bit address device is spotted 'in the wild', we |
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can and will add proper support. Right now, 10 bit address devices |
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are defined by the I2C protocol, but we have never seen a single device |
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which supports them. |
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