35 lines
1.6 KiB
Text
35 lines
1.6 KiB
Text
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The known details about autoacking.
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1) Auto-acking is disabled if promiscuous mode in enabled. Auto-acking
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is enabled when promiscuous mode is disabled. A more proper name
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for this bit would be promiscuous/#autoack.
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2) If promiscuous mode is disabled and a recieved packet 1) matches
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the address filters and 2) has the ack request bit set, then an
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auto-ack will be sent (provided you do item 3 properly). The
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sequence number is stuffed and transmitted automatically. Note: you
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must have the address set properly in the maca hardware. That means
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the EUI registers for long addressing and the PANID and short
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addr. for short addressing.
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3) You must wait 200 maca clocks or so after receiving a packet that
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needs an ack. This is necessary for the maca to do it's thing. If
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you don't wait enough then it either will not send the ack, or if
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you wait a little more (but not enough), the ack DSN will be zero.
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4) The following must be set properly, TXACKDELAY, RXACKDELAY,
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RXEND. The best way to set these is to use a scope and the TX_ON
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and RX_ON signals. You set TXACKDELAY so that the ack is
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transmitted 12 symbols after the received packet (192 us). You set
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RXACKDELAY to start before the ack is due to arrive (I'm doing
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100us before). And you set RXEND to be long enough to receive the
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ACK (I'm doing a 700us window or so).
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4b) CCA has its own set of timings.
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5) The transmitter must set TXSEQNR before MACA_DMATX.
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6) The status of the next "action complete" on the TX side tells you
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if the ack was received or not. Status will be 0 (success) if you
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got the ack and 5 (no_ack) if you did not.
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