stmpe812a STMicroelectronics, stmpe812a Datasheet
stmpe812a
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stmpe812a Summary of contents
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... Order code STMPE812ABJR March 2011 with PWM and dedicated RESET pin Description The STMPE812A is a 4-wire resistive touchscreen controller with 4-bit port expander integrated. The touchscreen controller is designed to be fully autonomous, requiring only minimal CPU intervention for sampling, filtering and pre- processing operations ...
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... I2C features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2 Data input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3 Read operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.4 Write operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4 Charge pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 5 Power modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6 STMPE812A registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 6.1 Auto-increment/non auto-increment address . . . . . . . . . . . . . . . . . . . . . . 17 7 System and identification registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 8 Interrupt system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 9 ADC controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 10 PWM controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 10.1 Register map for PWM function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 10.2 Interrupt of PWM controller ...
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... STMPE812A 12 GPIO port controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 13 Electrical specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 13.1 DC electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 13.2 AC electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 14 Package mechanical section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 15 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Doc ID 18225 Rev 2 Contents 3/52 ...
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... STMPE812A functional overview 1 STMPE812A functional overview The STMPE812A consists of the following blocks: 2 ● interface ● GPIO/PWM controller ● Touchscreen controller (TSC) ● Analog-to-digital converted (ADC) ● Driver and switch control unit Figure 1. STMPE812A block diagram VDD GND SDA SCL ...
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... Ground and GPIO drive clock (fail safe, tolerant to 3.6 V regardless data (fail safe, tolerant to 3.6 V regardless mA/- GPIO-2/ INT (3.6 V tolerant within V 3.3 V range) Doc ID 18225 Rev 2 STMPE812A functional overview Function valid CC valid CC 5/52 ...
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... STMPE812A functional overview Table 2. Pin assignments (continued) Pin Name Note: All I/O operates HBM ESD on all touchscreen pins (+/- GND) 0.5 µA max input leakage as input, across V 4 µs hardware filter on the 3 GPIOs as input 1.2 Typical application Figure 3. ...
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... STMPE812A interface For the bus master to communicate to the slave device, the bus master must initiate a Start condition and be followed by the slave device address. Accompanying the slave device address, there is a read/write bit (R/W). The bit is set to 1 for read and 0 for write operation. ...
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... The device samples the data input on SDATA on the rising edge of the SCLK. The SDATA signal must be stable during the rising edge of SCLK and the SDATA signal must change only when SCLK is driven low. 8/ interface are listed below: (1. 3 specification version 2.1 ADDR (P0 Doc ID 18225 Rev 2 STMPE812A 2 7-bit I C slave address 40h 41h ...
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... STMPE812A Table 5. Operating modes Mode Read Write Byte Programming sequence Start, Device address, R Register address to be read Restart, Device address, R Data Read, Stop If no Stop is issued, the Data Read can be continuously performed. If the register address falls within the range that allows an address auto- ≥ ...
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... Address Address Address Reg Device Device Address Address Address Data Device Reg to be Address Address written Reg Device Data to Data to Address Address Write Write + 1 Master Slave Doc ID 18225 Rev 2 STMPE812A Data Read Data Data Data Read Read + 1 Read + 2 Data to Write + 2 AM04175V1 ...
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... STMPE812A 2.3 Read operation A write is first performed to load the register address into the Address Counter but without sending a Stop condition. Then, the bus master sends a reStart condition and repeats the Device Address with the R/W bit set to 1. The slave device acknowledges and outputs the content of the addressed byte ...
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... Power supply The STMPE812A GPIO operates from a supply pin V immunity, V above 2 recommended. CC Power up reset The STMPE812A is equipped with an internal POR circuit that holds the device in reset state, until the V CC 12/52 supply input is valid. The internal POR is tied to the V Doc ID 18225 Rev 2 STMPE812A ...
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... STMPE812A 4 Charge pump The STMPE812A is integrated with an internal charge-pump. The charge pump is required for any ADC/TSC operations when V Activating the charge pump when V device. is less than 2 > 2.5 V may result in permanent damage of the CC Doc ID 18225 Rev 2 Charge pump 13/52 ...
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... Power modes 5 Power modes The STMPE812A operates states: active and hibernate. Active: – Whenever PEN-DOWN is detected, the device remains in active mode – Whenever PWM is active, the device remains in active mode – Whenever ADC is active, the device remains in ACTIVE MODE Hibernate: -PWM/ADC must be “ ...
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... On power up reset, device goes to active state. However, as all the functional blocks are clocked off by default, no touch/hotkey activity is possible. If there are no I device goes into auto-hibernate mode automatically. The auto-hibernate feature of STMPE812A is always enabled. Whenever there is a period of inactivity, the device enters this mode to reduce power consumption. On detection a touch, correctly addressed I As the device is able to wake up very quickly, there is no loss of touch data ...
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... STMPE812A registers 6 STMPE812A registers This section lists and describes the registers of the STMPE812A device, starting with a register map and then provides detailed descriptions of register types. Table 7. Register summary map table Address Register name Registers from 0x00 - 0x0F are always accessible. 0x00 - 01 ...
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... Auto-increment/non auto-increment address The STMPE812A supports auto-increment accesses on all, except for TSC data register (0x44). While accessing auto-increment register location, consecutive read/write access data from the consecutive registers. Note that for register accesses started on auto- incremental addresses, the address 0x44 is skipped. ...
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... R/W 8 R RESERVED PWM_OFF Doc ID 18225 Rev 2 STMPE812A Reset Function 0x0A812 Device identification Revision number 0x10 0x10 for engineering sample 0xF8 System control register 0x00 Port function control register General purpose storage 0x00 register System control register 2 1 GPIO_OFF ...
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... STMPE812A PORT_FUNCTION PORT 2 FUNCTION RESERVED Address: 0x04 Type: R/W Reset: 0xF8 Description: Port function control register. [7:6] PORT 2 FUNCTION [5:4] RESERVED [3:2] PORT 1 FUNCTION [1:0] PORT 0 FUNCTION Port function: '00' - GPIO input '01' - GPIO output '10' - ADC input (P1 only) '11' - Special function Special function for NONE P1 - PWM P2 - INT output ...
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... Interrupt system 8 Interrupt system The STMPE812A uses a 2-tier interrupt structure. In normal mode, interrupts from the GPIO and touchscreen controller assert the INT pin and are available in the Interrupt Status register (ISR). In pen down mode, the INT pin is asserted as long as pen down is detected. ...
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... STMPE812A INT_CTRL INT_MODE RESERVED 0 Address: 0x08 Type: R/W Reset: 0x00 Description: This register is used to enable the interruption from a system related interrupt source to the host. [7] INT_MODE: ‘0’ for Pen-Down INT mode (INT pin asserted as long as pen down detected). Nothing can de- assert the INT pin as long as PEN is down ...
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... P0 Port 0 activity (GPIO) [1] TSC_DATA Touch data available [0] TSC_TOUCH Touch is detected Note: * Hotkey interrupt should have respond time of <5 µs in active mode and less than hibernate mode. 22/ RESERVED Doc ID 18225 Rev 2 STMPE812A Interrupt enable register 1 0 TSC_DATA TSC_TOUCH 0 0 ...
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... STMPE812A ISR 7 6 TSC_ERR TSC_RELEASE 0 0 Address: 0x0A Type: R Reset: 0x00 Description: ISR register monitors the status of the interruption from a particular interrupt source to the host. Regardless whether the INT_EN bits are enabled, the ISR bits are still updated. Writing to this register has no effect. Reading the register clears any asserted bit Implementation: A shadow register MUST be used to ensure that Read+Clear action DOES NOT clear up any bit that is not READ ...
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... ADC controller 9 ADC controller A 12-bit ADC is integrated in the STMPE812A. The ADC could be used as generic analog- digital converter touchscreen controller capable of controlling a 4-wire resistive touchscreen. The ADC works ONLY with internal reference (equal to V Table 9. Address Register name 0x20 ADC control ...
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... STMPE812A ADC control register ADC_MODE ADC_CAP ADC_FREQ Address: 0x20 Type: R/W Reset: 0x33 Description: This register is used to configure the ADC operations. [7] ADC_MODE: ADC capture mode ‘0’ – Continuous capture according to sampling rate specified by ADC_FREQ register. New data over-writes old data in ADC_DATA register. ...
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... C master accesses the data register, upper/lower byte consistency must be guaranteed (once access starts, content will only be updated after BOTH bytes has been 2 read master accesses other register address): - 0x21 is LSB - 0x22 is MSB 26/ ADC_DATA_2 Doc ID 18225 Rev 2 STMPE812A ADC data register 1 0 ADC_DATA_1 ADC_DATA_0 0 0 ...
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... STMPE812A 10 PWM controller The PWM allows the brightness control of a LED/motor driver. The PWM uses base clock that is ½ of the OSC frequency (typically 600 kHz). The base clock is divided by a programmable DIV[4:0], which scales it to 18.75-600 kHz. This clock goes into PWM controller and outputs a signal that is pulse-width modulated (16 steps), with a frequency 16 times smaller ...
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... PWM Output “LOW” when PWM not running 0 Enable Writing ‘1’ to this bit starts the PWM controller sequence Writing ‘0’ has stops it Reads ‘1’ when PWM is running. 28/ BurstMultiplier 0 Doc ID 18225 Rev 2 STMPE812A PWM control1 register 1 0 Off_State Enable 0 0 ...
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... STMPE812A 10.2 Interrupt of PWM controller When non-infinite sequence is used, the completion of the PWM sequence causes the P0 bit in interrupt status register to be asserted. Doc ID 18225 Rev 2 PWM controller 29/52 ...
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... Touchscreen controller 11 Touchscreen controller The STMPE812A is integrated with a hard-wired touchscreen controller for 4-wire resistive type touchscreen. The touchscreen controller is able to operate completely autonomously, and would interrupt the connected CPU only when pre-defined event occurs. The TSC is based on an internal 20Ksamples/sec ADC, running off a 1 MHz (minimum 880 kHz) RC OSC ...
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... STMPE812A 11.1 Touchscreen controller detection sequence Following is the sequence of detection in the STMPE812A touchscreen controller for X, Y and Z: 1. Touch detect 2. Drive Y 3. Wait for settling time 4. Measure Y 5. Stop drive 6. Drive Z 7. Wait for settling time 8. Measure Z 9. Stop drive 10. Drive X 11. Wait for settling time 12 ...
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... Register name 0x40 TSC_CTRL 0x41 TSC_DET_CFG1 0x42 TSC_DET_CFG2 TSC_SAMPLING 0x43 0x44 TSC_DATA 32/52 Bit Type 8 R/W 8 R/W 8 R/W 8 R/W _RATE 8 R Doc ID 18225 Rev 2 STMPE812A Reset Function 0x00 Touchscreen control 0xA4 Touchscreen detection config 1 0xB0 Touchscreen detection config 2 0x0A Touchscreen sampling rate - Touchscreen data ...
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... STMPE812A TSC CTRL MAV_MODE[2:0] 0 Address: 0x40 Type: R/W Reset: 0x00 Description: Touchscreen control register. [7:5] MAV_MODE[2:0] ‘000’ – MAV filter disabled ‘001’ – 6 remove 2 ‘010’ – 8 remove 4 ‘011’ – 10 remove 2 ‘100’ – 12 remove 4 ‘101’ – 20 remove 4 ‘ ...
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... For large panels (> 6 inches), a capacitor recommended at the touchscreen terminals for noise filtering. In this case, settling time more is recommended. 34/52 TSC detection configuration 1 register TDetDly[2: Doc ID 18225 Rev 2 STMPE812A 1 0 Settling[2: ...
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... This field cannot be written on, when EN=1 [3:0] Z-Divider[3:0] Pen-Pressure is internally calculated as a 16-bit integer. As 16-bit resolution is typically not required for touchscreen operation, STMPE812A right-shifts the value internally by Z- Divider[3:0]. Z-value read through the TSC Data register is the lowest 8-bit of the shifted value. TSC detection configuration 2 register ...
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... ACQ in user initiated acquisition mode. In mode ‘10’, every time sampling is completed, it overwrites the buffer, and reset the data pointer 36/ SAMPLING TSC_DATA_2 Doc ID 18225 Rev 2 STMPE812A TSC sampling rate register Touchscreen data register 1 0 TSC_DATA_1 TSC_DATA_0 0 0 ...
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... STMPE812A Table 13. Touchscreen controller data register TSCDetectConfig2 OpMode StatusRead Data Valid Status Byte Structure 7 6 [7:2] RESERVED [1] DATA VALID 1: Touch data available/valid 0: Touch data not available/not valid Bit reset upon read [0] RESERVED Data Valid Status Read in data port is useful together with Pen Down mode whereby ...
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... If data is available, read data. Note: If one set of data is available in buffer, and not accessed by the I timer is up for the next data, the STMPE812A samples the next data as scheduled. If old data is still NOT accessed when new data is ready to be written to the buffer over- written. ...
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... STMPE812A The STMPE812A samples a new data set immediately after every complete read. If the host does not complete a data-set read, no further samples are taken. For each data point (4 bytes), number of I2C transaction required is: A: read Data Valid Status (1 byte), read data (4 bytes) ...
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... GPIO port controller 12 GPIO port controller A total of 3 configurable ports are available in the STMPE812A port expander device. If configured as GPIO input/output, they are controlled by the GPIO registers. Table 14. GPIO registers Address 0x10 0x11 0x12 0x13 0x14 All GPIO registers are named as GPxx, where: ...
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... STMPE812A 13 Electrical specification Table 16. Absolute maximum rating Symbol V Supply voltage CC Vi-i2c Input voltage at SDA/SCL Vi-io Input voltage at P0-P5 On all touchscreen and GPIO pins (HBM) ESD On all other pins (HBM) Table 17. Thermal data Symbol Thermal resistance junction-ambient T J (Flip-chip12) T Operating temperature T Storage temperature STG Table 18 ...
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... Min Typ 0.20 V -0.3 – 0.80 V – 0.45 -0.3 – 0.85 V – 3.6 V – 0.1 IN Min Typ – – – – STMPE812A Max Unit µA µA 1 µA Max Unit +0 +0.3 V 0.5 µA Max Unit 400 KHz 120 KHz ...
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... STMPE812A Table 20. AC electrical characteristics (-40 ° °C) Symbol Minimum RESET pulse T RESET width Minimum INPUT width T required for GPIO state IN transition Internal RC OSC F osc frequency Internal RC OSC F osc frequency Table 21. ADC specification Parameter Full-scale input span Absolute input range Input capacitance ...
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... Drive current ( limit) 44/52 Test conditions Min V = 1.65 -3 X+/X- or Y+/Y- shorted together externally V =1.65 -3 X+/X- or Y+/Y- – shorted together externally V =1.65 -3 X+/X- or Y+/Y- – shorted together externally V =1.65 -3.6V CC X+/X- or Y+/Y- – shorted together externally Doc ID 18225 Rev 2 STMPE812A Typ Max Unit 10 mA – – – ...
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... STMPE812A 14 Package mechanical section In order to meet environmental requirements, ST offers these devices in different grades of ® ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at: www.st.com. ® ECOPACK trademark. Figure 9. Package outline for Flip-chip CSP 12 ...
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... ccc $ Figure 10. Footprint recommendation 46/52 Millimeters Min Typ 0.585 0.650 0.21 0.25 – 0.35 0.265 0.315 2.12 2.17 – 1.5 1.62 1.67 – 1.0 0.45 0.5 – 0.335 – 0.335 – 0.25 – 0.08 – 0.05 Doc ID 18225 Rev 2 STMPE812A Max 0.715 0.29 – 0.365 2.22 – 1.72 – 0.55 – – – – – ...
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... STMPE812A Figure 11. Tape information Table 24. Tape specifications Symbol 10Po Millimeters Min Typ 1.78 1.83 2.34 2.29 0.68 0.73 3.45 3.50 1.65 1.75 7.90 8.00 1.95 2.00 3.90 4.00 39.80 40.00 1.50 1.55 0.185 0.200 3.90 4.00 Doc ID 18225 Rev 2 Package mechanical section Max 1.88 2.34 0.78 3.55 1.85 8.30 2.05 4.10 40.20 1.60 0.215 4.10 47/52 ...
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... Package mechanical section Figure 12. Tape orientation 1. Pin top left corner based on above tape orientation. Figure 13. Device marking 48/52 User direction of feed Doc ID 18225 Rev 2 STMPE812A AM00745V1 ...
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... STMPE812A Figure 14. Reel drawing (front) Figure 15. Reel drawing (back) Doc ID 18225 Rev 2 Package mechanical section 49/52 ...
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... Package mechanical section Table 25. Tape width (millimeters) Tape width 8 50/ max min max 180 60 8,4 Doc ID 18225 Rev 2 STMPE812A W2 W3 max min max 14.4 7.9 10.9 ...
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... STMPE812A 15 Revision history Table 26. Document revision history Date 18-Nov-2010 09-Mar-2011 Revision 1 Initial release. Document status promoted from preliminary data to datatasheet. 2 Updated Table 2. Doc ID 18225 Rev 2 Revision history Changes 51/52 ...
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... Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America 52/52 Please Read Carefully: © 2011 STMicroelectronics - All rights reserved STMicroelectronics group of companies www.st.com Doc ID 18225 Rev 2 STMPE812A ...