NAME
ds3231 — Extremely Accurate i2c-integrated RTC/TCXO/CrystalSYNOPSIS
device iicdevice iicbus
device ds3231
DESCRIPTION
The ds3231 is a low-cost, extremely accurate I2C realtime clock (RTC) with an integrated temperature-compensated crystal oscillator (TCXO) and crystal. The device incorporates a battery input and maintains accurate timekeeping when main power to the device is interrupted. Access to ds3231 data is made with the sysctl(8) interface:dev.ds3231.0.%desc: Maxim DS3231 RTC dev.ds3231.0.%driver: ds3231 dev.ds3231.0.%location: addr=0xd0 dev.ds3231.0.%pnpinfo: name=rtc compat=maxim,ds3231 dev.ds3231.0.%parent: iicbus1 dev.ds3231.0.temperature: 23.2C dev.ds3231.0.temp_conv: 0 dev.ds3231.0.bbsqw: 0 dev.ds3231.0.sqw_freq: 8192 dev.ds3231.0.sqw_mode: interrupt dev.ds3231.0.32khz_enable: 1
- dev.ds3231.%d.temperature
- The read-only value of the current temperature read by the RTC.
- dev.ds3231.%d.temp_conv
- Start a new temperature conversion. When read as 1, a temperature conversion is in progress. When read as 0 and then set to 1, a temperature conversion is started. The temperature conversion runs automatically on power up and once every 64 seconds afterward.
- dev.ds3231.%d.bbsqw
- If set to 1 and dev.ds3231.%d.sqw_mode is set to square-wave, battery-backed square-wave output is enabled. If set to 0, the SQW pin will be set to high impendance when the RTC is being powered by battery.
- dev.ds3231.%d.sqw_freq
- Select the frequency of the SQW pin when the square-wave output is enabled on dev.ds3231.%d.sqw_mode. It can be set to 1, 1024, 4096, and 8192.
- dev.ds3231.%d.sqw_mode
- Set the operation mode for the SQW pin. It can be set to 'interrupt' (default) or 'square-wave'. In interrupt mode, the SQW pin is used to generate interrupts for the RTC alarms. In square-wave mode, the SQW pin drives a square-wave of dev.ds3231.%d.sqw_freq frequency.
- dev.ds3231.%d.32khz_enable
- Enable the 32kHz output.
MIPS
, these values are configurable for
ds3231:
- hint.ds3231.%d.at
- The iicbus(4) that the ds3231 is connected to.
- hint.ds3231.%d.addr
- The 8-bit i2c address of ds3231. The default 8-bit address for ds3231 is 0xd0.
- compatible
- Must always be set to "maxim,ds3231".
- reg
- The 7-bit i2c address of ds3231. The default 7-bit address for ds3231 is 0x68.
SEE ALSO
fdt(4), iic(4), iicbus(4), sysctl(8)HISTORY
The ds3231 driver first appeared in FreeBSD 11.0.AUTHORS
The ds3231 driver and this manual page were written by Luiz Otavio O Souza <[email protected]>.February 12, 2016 | Debian |