GigaDevice Semiconductor GD32F3x0 - Touch Sensing Interface (TSI); Overview; Characteristics; Function Overview

GD32F3x0 User Manual
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22. Touch sensing interface (TSI)
22.1. Overview
Touch Sensing Interface (TSI) provides a convenient solution for touch keys, sliders and
capacitive proximity sensing applications. The controller builds on charge transfer method.
Placing a finger near fringing electric fields adds capacitance to the system and TSI is able to
measure this capacitance change using charge transfer method.
22.2. Characteristics
 Charge transfer sequence fully controlled by hardware.
 6 fully parallel groups implemented.
 18 IOs configurable for capacitive sensing Channel Pins and 6 for Sample Pins.
 Configurable transfer sequence frequency.
 Able to implement the user specific charge transfer sequences.
 Sequence end and error flags / configurable interrupts.
 Spread spectrum function implemented.
22.3. Function Overview
22.3.1. TSI block diagram
Figure 22-1. Block diagram of TSI module
TSI registers
AHB Bus
Group 0 IO
Controller
Pulse Clock
Generators
G0_IO0
Charge Transfer
Sequence FSM
G0_IO3
G0_IO2
G0_IO1
Group 1 IO
Controller
G1_IO0
G1_IO3
G1_IO2
G1_IO1
Group 5 IO
Controller
G5_IO0
G5_IO3
G5_IO2
G5_IO1
TSI Counters
22.3.2. Touch sensing technique overview
There are different technologies for touch sensing, such as optical, resistive, capacitive,