STMPE811QTR STMicroelectronics

STMPE811 S-Touch advanced resistive touchscreen controller with 8-bit GPIO expander Features 8 GPIOs 1.8 - 3.3 V operating voltage Integrated 4-wire touchscreen controller Interrupt output pin Wakeup feature on each I/O QFN16 2 SPI and I C interface (3x3) Up to 2 devices sharing the same bus in 2 I C mode (1 address line) 8-input 12-bit ADC Description 128-depth buffer touchscreen controller The STMPE811 is a GPIO (general purpose Touchscreen movement detection algorithm input/output) port expander able to interface a main digital ASIC via the two-line bidirectional bus 25 kV air-gap ESD protection (system level) 2 (I C). A separate GPIO expander is often used in 4 kV HBM ESD protection (device level) mobile multimedia platforms to solve the problems of the limited amount of GPIOs typically available on the digital engine. Applications The STMPE811 offers great flexibility, as each I/O can be configured as input, output or specific Portable media players functions. The device has been designed with Game consoles very low quiescent current and includes a wakeup feature for each I/O, to optimize the power Mobile and smartphones consumption of the device. GPS A 4-wire touchscreen controller is built into the STMPE811. The touchscreen controller is enhanced with a movement tracking algorithm (to avoid excessive data), a 128 x 32 bit buffer and programmable active window feature. Table 1. Device summary Order code Package Packaging STMPE811QTR QFN16 Tape and reel September 2011 Doc ID 14489 Rev 6 1/65 www.st.com 65Contents STMPE811 Contents 1 STMPE811 functional overview 6 2 Pin configuration and functions . 7 2.1 Pin functions 8 3 I2C and SPI interface . 9 3.1 Interface selection . 9 4 I2C interface . 10 4.1 I2C features . 12 4.2 Data input . 13 4.3 Read operation . 14 4.4 Write operations 14 5 SPI interface . 15 5.1 SPI protocol definition . 15 5.1.1 Register reading 15 5.1.2 Register write . 16 5.1.3 Termination of data transfer 16 5.2 SPI timing modes . 17 5.2.1 SPI timing definition 17 6 STMPE811 registers 19 7 System and identification registers 22 8 Interrupt system . 25 9 Analog-to-digital converter 29 10 Touchscreen controller 33 10.1 Driver and switch control unit 33 10.2 Touch detect delay 39 2/65 Doc ID 14489 Rev 6