35 lines
1.1 KiB
Text
35 lines
1.1 KiB
Text
It is often useful to control the memory layout of fields in a data structure to match an interface control definition, or to interface with hardware. Define a data structure matching the RS-232 Plug Definition. Use the 9-pin definition for brevity.
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Pin Settings for Plug
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(Reverse order for socket.)
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__________________________________________
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1 2 3 4 5 6 7 8 9 10 11 12 13
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14 15 16 17 18 19 20 21 22 23 24 25
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_________________
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1 2 3 4 5
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6 7 8 9
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25 pin 9 pin
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1 - PG Protective ground
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2 - TD Transmitted data 3
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3 - RD Received data 2
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4 - RTS Request to send 7
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5 - CTS Clear to send 8
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6 - DSR Data set ready 6
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7 - SG Signal ground 5
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8 - CD Carrier detect 1
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9 - + voltage (testing)
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10 - - voltage (testing)
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11 -
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12 - SCD Secondary CD
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13 - SCS Secondary CTS
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14 - STD Secondary TD
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15 - TC Transmit clock
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16 - SRD Secondary RD
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17 - RC Receiver clock
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18 -
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19 - SRS Secondary RTS
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20 - DTR Data terminal ready 4
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21 - SQD Signal quality detector
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22 - RI Ring indicator 9
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23 - DRS Data rate select
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24 - XTC External clock
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25 -
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