
DS3232M
±5ppm, I2C Real-Time Clock with SRAM
17
Maxim Integrated
Status Register (0Fh)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
OSF
BB32KHZ
0
EN32KHZ
BSY
A2F
A1F
1
0
1
X
BIT 7
OSF: Oscillator stop flag. A logic 1 in this bit indicates that the oscillator either is stopped or was stopped for
some period and could be used to judge the validity of the timekeeping data. This bit is set to logic 1 any time
that the oscillator stops. This bit remains at logic 1 until written to logic 0. The following are examples of
conditions that can cause the OSF bit to be set:
1) The first time power is applied.
2) The voltages present on both VCC and VBAT are insufficient to support the oscillator.
3) The EOSC bit is turned off in battery-backed mode.
4) External influences on the oscillator (i.e., noise, leakage, etc.).
BIT 6
BB32KHZ: Battery-backed 32kHz output (BB32KHZ). This bit enables the 32kHz output when the device is pow-
ered from VBAT (provided the 32kHz output is enabled with the EN32KHZ bit). If BB32KHZ = 0, the 32kHz output
is forced low when the device is powered by VBAT.
BITS 5:4
Unused (0). These bits have no meaning and are fixed at 0 when read.
BIT 3
EN32KHZ: Enabled 32.768kHz output. This bit enables and disables the 32KHZ output. When set to a logic 0,
the 32KHZ output is high impedance. On initial power-up, this bit is set to a logic 1 and the 32KHZ output is
enabled and produces a 32.768kHz square wave if the oscillator is enabled.
BIT 2
BSY: Busy. This bit indicates the device is busy executing temperature conversion function. It goes to logic 1
when the conversion signal to the temperature sensor is asserted, and then it is cleared when the device has
completed the temperature conversion. See the Block Diagram for more details.
BIT 1
A2F: Alarm 2 flag. A logic 1 in the alarm 2 flag bit indicates that the time matched the alarm 2 registers. If the
A2IE bit is logic 1 and the INTCN bit is set to logic 1, INT/SQW is also asserted. A2F is cleared when written to
logic 0. This bit can only be written to logic 0. Attempting to write to logic 1 leaves the value unchanged.
BIT 0
A1F: Alarm 1 flag. A logic 1 in the alarm 1 flag bit indicates that the time matched the alarm 1 registers. If the
A1IE bit is logic 1 and the INTCN bit is set to logic 1, INT/SQW is also asserted. A1F is cleared when written to
logic 0. This bit can only be written to logic 0. Attempting to write to logic 1 leaves the value unchanged.