2 .\" Copyright (c) 2014 Luiz Otavio O Souza <loos@freebsd.org>
3 .\" All rights reserved.
5 .\" Redistribution and use in source and binary forms, with or without
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32 .Nd Extremely Accurate i2c-integrated RTC/TCXO/Crystal
40 is a low-cost, extremely accurate I2C realtime clock (RTC) with an
41 integrated temperature-compensated crystal oscillator (TCXO) and crystal.
43 The device incorporates a battery input and maintains accurate timekeeping
44 when main power to the device is interrupted.
52 dev.ds3231.0.%desc: Maxim DS3231 RTC
53 dev.ds3231.0.%driver: ds3231
54 dev.ds3231.0.%location: addr=0xd0
55 dev.ds3231.0.%pnpinfo: name=rtc compat=maxim,ds3231
56 dev.ds3231.0.%parent: iicbus1
57 dev.ds3231.0.temperature: 23.2C
58 dev.ds3231.0.temp_conv: 0
60 dev.ds3231.0.sqw_freq: 8192
61 dev.ds3231.0.sqw_mode: interrupt
62 dev.ds3231.0.32khz_enable: 1
64 .Bl -tag -width ".Va dev.ds3231.%d.temperature"
65 .It Va dev.ds3231.%d.temperature
66 The read-only value of the current temperature read by the RTC.
67 .It Va dev.ds3231.%d.temp_conv
68 Start a new temperature conversion.
69 When read as 1, a temperature conversion is in progress.
70 When read as 0 and then set to 1, a temperature conversion is started.
71 The temperature conversion runs automatically on power up and once every 64
73 .It Va dev.ds3231.%d.bbsqw
75 .Va dev.ds3231.%d.sqw_mode
76 is set to square-wave, battery-backed square-wave output is enabled.
77 If set to 0, the SQW pin will be set to high impendance when the RTC is
78 being powered by battery.
79 .It Va dev.ds3231.%d.sqw_freq
80 Select the frequency of the SQW pin when the square-wave output is enabled on
81 .Va dev.ds3231.%d.sqw_mode .
82 It can be set to 1, 1024, 4096, and 8192.
83 .It Va dev.ds3231.%d.sqw_mode
84 Set the operation mode for the SQW pin.
85 It can be set to 'interrupt' (default) or 'square-wave'.
86 In interrupt mode, the SQW pin is used to generate interrupts for the RTC
88 In square-wave mode, the SQW pin drives a square-wave of
89 .Va dev.ds3231.%d.sqw_freq
91 .It Va dev.ds3231.%d.32khz_enable
92 Enable the 32kHz output.
97 datasheet for more details.
101 based system, such as
103 these values are configurable for
105 .Bl -tag -width ".Va hint.ds3231.%d.addr"
106 .It Va hint.ds3231.%d.at
112 .It Va hint.ds3231.%d.addr
113 The 8-bit i2c address of
115 The default 8-bit address for
122 based system the following properties must be set:
123 .Bl -tag -width ".Va compatible"
125 Must always be set to "maxim,ds3231".
127 The 7-bit i2c address of
129 The default 7-bit address for
141 driver first appeared in
147 driver and this manual page were written by
148 .An Luiz Otavio O Souza Aq Mt loos@FreeBSD.org .