STCN75_08 Datasheet, PDF (15/35 Pages) STMicroelectronics – Digital temperature sensor and thermal watchdog

STCN75
3
Functional description
Functional description
3.1
3.1.1
The STCN75 registers have unique pointer designations which are defined in Table 5 on
page 16. Whenever any READ/WRITE operation to the STCN75 register is desired, the
user must “point” to the device register to be accessed.
All of these user-accessible registers can be accessed via the digital serial interface at
anytime (seeSection 3.3: Serial interface on page 19), and they include:
● Command register/address pointer register
● Configuration register
● Temperature register
● Over-limit signal temperature register (T_OS)
● Hysteresis temperature register (T_HYS)
Registers and register set formats
Command/pointer register
The most significant bits (MSBs) of the command register must always be zero. Writing a '1'
into any of these bits will cause the current operation to be terminated (bit 2 through bit 7
must be kept '0', see Table 4).
Table 4. Command/pointer register format
MSB
LSB
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
0
0
0
0
0
0
P1
P0
These bits must be ‘O’
Pointer/register
select bits
The command register retains pointer information between operations (see Table 5).
Therefore, this register only needs to be updated once for consecutive READ operations
from the same register. All bits in the command register default to '0' at power-up.
15/35