HT45F75 Datasheet, PDF (112/190 Pages) Holtek Semiconductor Inc – Body Fat Scale Flash MCU

HT45F75
Body Fat Scale Flash MCU
Temperature sensor
This device provides an internal temperature sensor to compensate the device due to temperature
effects. By selecting the PGA input channels to be VTSO+ and VTSO-, the ADC can obtain
temperature information and the designer can then implement some compensation on the A/D
converted data. The following block diagram illustrates the functional operation of the temperature
sensor.
AVDD
I
V_TSO+
V_TSO-
PGA
ADC
AVSS
Serial Interface Module – SIM
This device contains a Serial Interface Module, which includes both the four line SPI interface and
the two line I²C interface types, to allow an easy method of communication with external peripheral
hardware. Having relatively simple communication protocols, these serial interface types allow the
microcontroller to interface to external SPI or I²C based hardware such as sensors, Flash memory,
etc. As both interface types share the same pins and registers, the choice of whether the SPI or I²C
type is used is made using the SIM operating mode control bits, named SIM2~SIM0, in the SIMC0
register. These pull-high resistors of the SIM pin-shared I/O pins are selected using pull-high control
registers when the SIM function is enabled and the corresponding pins are used as SIM input pins.
SPI Interface
The SPI interface is often used to communicate with external peripheral devices such as sensors,
Flash memory devices etc. Originally developed by Motorola, the four line SPI interface is a
synchronous serial data interface that has a relatively simple communication protocol simplifying
the programming requirements when communicating with external hardware devices.
The communication is full duplex and operates as a slave/master type, where the device can be
either master or slave. Although the SPI interface specification can control multiple slave devices
from a single master, but this device is provided only one SCS pin. If the master needs to control
multiple slave devices from a single master, the master can use I/O pin to select the slave devices.
Rev. 1.10
112
December 14, 2016