1 //---------------------------------------------------------------------------
2 // Copyright (C) 1999 Dallas Semiconductor Corporation, All Rights Reserved.
3 //
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23 // shall not be used except as stated in the Dallas Semiconductor
24 // Branding Policy.
25 //---------------------------------------------------------------------------
26 //
27 // DS520SES.C - Acquire and release a Session for general 1-Wire Net
28 // library
29 //
30 // Version: 2.00
31 // 1.03 -> 2.00 Changed 'MLan' to 'ow'. Added support for
32 // multiple ports.
33 //
34
35 #include "ownet.h"
36 #include <ds8xc520.h>
37
38 // Port for 1Wire communication. Defaults here, but defined in Makefile also
39 // WARNING: See appnote ??? to select an appropriate port pin and
40 // allow for appropriate protection of the pin.
41 // If this is changed, also change in link file
42 #ifndef OW_PORT
43 #define OW_PORT INT2
44 #endif
45
46 // defined in link file
47 extern void usDelay(int);
48
49 // local function prototypes
50 SMALLINT owAcquire(int,char *);
51 void owRelease(int);
52
53 //---------------------------------------------------------------------------
54 // Attempt to acquire a 1-Wire net
55 //
56 // 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
57 // indicate the symbolic port number.
58 // 'port_zstr' - zero terminated port name.
59 //
60 // Returns: TRUE - success, port opened
61 //
owAcquire(int portnum,char * port_zstr)62 SMALLINT owAcquire(int portnum, char *port_zstr)
63 {
64 port_zstr = 0;
65 portnum = 0;
66
67 OW_PORT = 1; // drive bus high.
68 usDelay(500); // give time for line to settle
69
70 // checks to make sure the line is idling high.
71 return (OW_PORT==1?TRUE:FALSE);
72 }
73
74 //---------------------------------------------------------------------------
75 // Release the previously acquired a 1-Wire net.
76 //
77 // 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
78 // indicate the symbolic port number.
79 //
owRelease(int portnum)80 void owRelease(int portnum)
81 {
82 portnum = 0;
83 }
84
85
86