EM MICROELECTRONIC - MARIN SA EM6420 Ultra Low Power Capacitive Touch Sensor Interface IC Description Availability The EM6420 is an ultra low power Touch Sensor Interface IC able to scan sequentially up to 16 capacitive sensors. The device parameters (number of used sensors, sensors scan frequency, sensors sensitivity level, IRQ condition) are configurable either from a host microcontroller through a communication port or through configuration inputs. • Naked die • SMT package MLF32-36-40 Recognised touch inputs will be signaled with an active edge at the IRQ pad and data are ready to be read through the communicaion port by the host MCU. Conditions for the IRQ to get active are configurable : at the end of every scan, at the end of a scan if at least one sensor is active or at the end of a scan if the sensors state has changed. The EM6420 can also detect the most active sensor in applications where sensors are tightly spaced. It compares relative levels among sensors and selects the sensor with the largest signal strength. To increase the number of sensors >16, use several EM6420 in parallel. Depending on the selected supply voltage range, 3 or 4 decoupling capacitors are required for the entire functionality of the EM6420 from -40 to + 85°C. Features • Up to 16 analogue sensor inputs • User selectable communication interfaces : 4-wire SPI, 2 I C, 4-bit parallel interface and 8-bit direct output • User-selectable active edge IRQ output signal • Active high enable input • No software development and tuning required • Development tools and documentations available • Complete touch module available: IC + electrodes design on various non-conductive substrates Electrical Characteristics Design Considerations • Supply voltage 1.2 V to 2.0 V or 2.2 to 3.6 V • Power consumption Low Power Mode 8.0 µA @ 3.0 V (14.5 µA @1.5 V) for 16 sensors scanned at 8 Hz 2.0 µA @ 3.0 V (5.0 µA @1.5 V) for 16 sensors scanned at 8 Hz The EM6420 is well suited for battery and mains powered applications where the following features are important : • • • Ultra Low Power Mode 3 to 31 pF Nominal sensor capacitance Sensors scan frequency • COM clock frequency Tamper proof applications • Nice and clean designs • Touch function to avoid buttons and keys • Slider functions • Hygienic issues, cleaning aspects • Waterproof designs Applications 1 Hz to 128 Hz *frequency depending on number of sensors up to 400 kHz Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 • 1 • Mobile phones, cordless phones • PDA, keyboards • White & brown goods • Toys • Lighting - Sliders for dimming www.emmicroelectronic.com EM6420 TABLE OF CONTENTS 1. PRELIMINARIES ............................................................................................................................................... 4 1.1 1.2 2. 3. GENERAL DESCRIPTION ................................................................................................................................ 5 FEATURES ........................................................................................................................................................ 6 3.1 3.2 3.3 3.4 3.5 4. 5. 6. 8.3 Introduction ............................................................................................................................................................ 20 EM6420 Communication Interfaces ....................................................................................................................... 21 8.2.1 Slave I2C Interface ................................................................................................................................ 21 8.2.2 Slave SPI Interface ................................................................................................................................ 22 8.2.3 Slave 4-bit Parallel Interface.................................................................................................................. 24 8.2.4 8-bit Direct Output Interface .................................................................................................................. 25 8.2.5 Communication interface initialization. .................................................................................................. 27 EM6420 Commands............................................................................................................................................... 28 8.3.1 Command startTS ................................................................................................................................. 29 8.3.2 Command stopTS ................................................................................................................................. 29 8.3.3 Command setTSMode........................................................................................................................... 29 8.3.4 Command selectBaseSettings .............................................................................................................. 30 8.3.5 Command selectAltSettings .................................................................................................................. 30 8.3.6 Command setBaseScanFreq ................................................................................................................ 31 8.3.7 Command setAltScanFreq .................................................................................................................... 31 8.3.8 Command setBaseHiSensNb ................................................................................................................ 32 8.3.9 Command setAltHiSensNb .................................................................................................................... 32 8.3.10 Command setBaseIRQCond ................................................................................................................. 33 8.3.11 Command setAltIRQCond ..................................................................................................................... 33 8.3.12 Command next (SPI protocol only)........................................................................................................ 34 8.3.13 Command end ....................................................................................................................................... 34 8.3.14 Command setThreshold ........................................................................................................................ 36 8.3.15 Command getAppSettings..................................................................................................................... 36 8.3.16 Command getVersion ............................................................................................................................ 36 8.3.17 Command getStatus .............................................................................................................................. 37 EM6420 COMMUNICATION FRAMES ........................................................................................................... 39 9.1 9.2 9.3 10. 11. 12. Standard Operating Conditions .............................................................................................................................. 16 Communication Interface ....................................................................................................................................... 16 8-bit Direct Output Interface ................................................................................................................................... 16 Slave I2C Interface ................................................................................................................................................. 16 Slave SPI Interface................................................................................................................................................. 17 Slave 4-bit Parallel Interface .................................................................................................................................. 19 EM6420 TO HOST CONTROLLER COMMUNICATION ................................................................................ 20 8.1 8.2 9. Absolute Maximum Ratings ...................................................................................................................................... 9 Handling Procedures ................................................................................................................................................ 9 Supply Voltage Configurations ................................................................................................................................. 9 Standard Operating Conditions .............................................................................................................................. 11 DC Characteristics – Power Supply ....................................................................................................................... 12 POR ....................................................................................................................................................................... 12 Touch Screen Interface .......................................................................................................................................... 13 Input pads CISX, CI8 and LSV ................................................................................................................................ 13 Input pad En ........................................................................................................................................................... 13 Output pad IRQ ...................................................................................................................................................... 14 Bidirectional pads CIO2 … CIO7 ............................................................................................................................. 14 Bidirectional pads CIO0 and CIO1 ......................................................................................................................... 15 TIMING SPECIFICATIONS .............................................................................................................................. 16 7.1 7.2 7.3 7.4 7.5 7.6 8. Key elements............................................................................................................................................................ 6 Power Supply ........................................................................................................................................................... 6 Interfaces ................................................................................................................................................................. 6 Development Tools .................................................................................................................................................. 6 Touch modules based on EM6420 IC ...................................................................................................................... 6 BLOCK DIAGRAM ............................................................................................................................................. 7 PAD DESCRIPTION .......................................................................................................................................... 7 ELECTRICAL SPECIFICATIONS ..................................................................................................................... 9 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 7. Reference ................................................................................................................................................................. 4 Conventions ............................................................................................................................................................. 4 2 Slave I C communication frame ............................................................................................................................. 40 Slave SPI communication frame ............................................................................................................................ 40 Slave 4-bit parallel communication frame............................................................................................................... 41 TYPICAL APPLICATIONS .............................................................................................................................. 43 PAD LOCATION DIAGRAM ............................................................................................................................ 46 PACKAGE INFORMATION ............................................................................................................................. 48 Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 2 www.emmicroelectronic.com EM6420 12.1 12.2 12.3 13. Sawn 40-pin Micro Lead Frame 2 – 6 x 6 mm body ............................................................................................... 48 Sawn 36-pin Micro Lead Frame 2 – 5 x 5 mm body ............................................................................................... 50 Sawn 32-pin Micro Lead Frame 2 – 5 x 5 mm body ............................................................................................... 52 ORDERING INFORMATION ............................................................................................................................ 54 Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 3 www.emmicroelectronic.com EM6420 1. PRELIMINARIES 1.1 REFERENCE [1] “The I2C-Bus Specification – Version 2.1”, Philips Semiconductors, January 2000 1.2 CONVENTIONS The following conventions will be used in this document: • Signals which are active low have names which start with the prefix “n_”. Example: n_rst. Signal names without this prefix are active high. • When qualifying a signal, the term “asserted” means that the signal is active, while the term “deasserted” or “negated” means that the signal is inactive regardless of whether the active state is represented by a high or low voltage. • When qualifying a bit within a register, the term “set” or “activated” means that the bit value is a high logic level, while the term “cleared” means that the bit value is a low logic level. • Signal busses are denoted with the range “[MSB:LSB]” where the index of the Most Significant Bit (MSB) is given first and the index of the Least Significant Bit (LSB) is given last. • Bit group within a register are denoted BMSB ... BLSB where the index of the Most Significant Bit (MSB) is given first and the index of the Least Significant Bit (LSB) is given last. • Hexadecimal numbers are followed by the index “H”. Example: 1F5AH. • Binary numbers are followed by the index “B”. Example: 1011B. • Register names followed by the index “H” refers to the high byte of a 16-bit register. • Register names followed by the index “L” refers to the low byte of a 16-bit register. Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 4 www.emmicroelectronic.com EM6420 2. GENERAL DESCRIPTION The EM6420 is a very low power ASIC that includes a Touch Screen interface able to handle up to 16 capacitive sensors. Several devices can be used in parallel to manage more than 16 sensors. The application parameters (number of used sensors, sensors scan frequency, sensors sensitivity level, IRQ condition …) are fully configurable either from a host microcontroller through a communication port or from several configuration inputs. VDD Host Microcontroller IO 100 nF IRQ COM port IO VDD IRQ S 0 - S 15 COM port En_TSI Connexion to Touch Screen Sensors EM6420 En VDDA 22 nF COMCfg port VSS Figure 2-1: VDDD 100 nF Typical Operating Configuration Depending on the IRQ condition parameter, a user-selectable IRQ active edge can be generated: • At the end of every scan. • At the end of a scan if the sensors state has changed. • At the end of a scan if either the sensors state has changed or at least one sensor is active. The sensors state can then be read by the host microcontroller through the communication port. The EM6420 can also detect the most activated sensor in applications where sensors are tightly spaced by comparing relative levels among sensors and by selecting the one with the largest signal strength. Supply voltage range can be selected either from 1.2 V to 2.0 V or from 2.2 V to 3.6 V. Depending on selected supply voltage range, 3 or 4 decoupling capacitors are required for overall functionality. No other external component is needed. The EM6420 can operate over a wide temperature range, from -40°C to +85°C. It is available in die form or in different SMT packages. 1 2 Ultra low current consumptions have been achieved with the EM6420 starter kit , typically : • • • • 8.0 µA @ 3.0 V (14.5 µA @1.5 V) for 16 sensors scanned at 8 Hz in Low Power Mode 2.0 µA @ 3.0 V (5.0 µA @1.5 V) for 16 sensors scanned at 8 Hz in Ultra Low Power Mode 5.0 µA @ 3.0 V (9.0 µA @1.5 V) for 8 sensors scanned at 2 Hz in Low Power Mode 0.7 µA @ 3.0 V (1.2 µA @1.5 V) for 8 sensors scanned at 2 Hz in Ultra Low Power Mode 1 Please ask EM Microelectronic-Marin SA for EM6420 starter kit availability 2 Other values may be obtained depending on electrode design and selected parameters Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 5 www.emmicroelectronic.com EM6420 3. FEATURES 3.1 KEY ELEMENTS • Ultra low power and ultra low voltage Touch Screen interface • Up to 16 sensor inputs per device • Increased number of sensors can be addressed with more devices in parallel • User selectable power supply range (see below) • User-selectable active edge IRQ output signal • User-selectable communication interface (see below) • Active high enable input • Maximum 4 external components needed (decoupling capacitors only) • No software development or tuning required 3.2 POWER SUPPLY • Low supply voltage range : 1.2 V to 2.0 V • High supply voltage range : 2.2 V to 3.6 V • Disabled Mode consumption : IDD Disabled < 50 nA • IDD = 8.0 µA @ 3.0 V (14.5 µA @ 1.5 V ) for 16 sensors scanned at 8 Hz in Low Power Mode • IDD = 2.0 µA @ 3.0 V (5.0 µA @ 1.5 V ) for 16 sensors scanned at 8 Hz in Ultra Low Power Mode • IDD = 5.0 µA @ 3.0 V (9.0 µA @ 1.5 V ) for 8 sensors scanned at 2 Hz in Low Power Mode • IDD = 0.7 µA @ 3.0 V (1.2 µA @ 1.5 V ) for 8 sensors scanned at 2 Hz in Ultra Low Power Mode • Internal voltage regulator for logic supply when used in high supply voltage range • Internal voltage multiplier for analog supply when used in low supply voltage range • Internal voltage regulator for analog supply 3.3 INTERFACES • 4-wire SPI • I C (Standard-Mode or Fast-Mode compatible) • 4-bit parallel interface • 8-bit direct output (Standalone Mode) 2 3.4 DEVELOPMENT TOOLS • EM6420 starter kit with its related documentation • Ultra low power User Interface reference design with EM6420-based Touch solution, EM6110 LCD driver and EM6819 host MCU 3.5 TOUCH MODULES BASED ON EM6420 IC • Capacitive electrodes design capability on various non-conductive substrates (according customer's requirements)" • Transparent / Invisible electrodes possible • Application-specific touch modules development: contact EM-Microelectronic HQ Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 6 www.emmicroelectronic.com EM6420 4. BLOCK DIAGRAM V CP CBL CBH S0 S1 S2 S3 ... ... Legend S12 S 13 S 14 S15 Powered by VDD Powered by VCP V DD Voltage Multiplier Touch Screen Interface RC Oscillator Analog Part - 16 sensor inputs 131 kHz LSV Power Supply Configuration Logic Touch Screen Interface Communication Controller V DDA Analog Supply Voltage Regulator CoolRISC Core V DDD Digital Supply Voltage Regulator DPMA Controller VSS Powered by VDDA Powered by VDDD Digital Part - 16 sensor inputs IRQ ® SPI RAM Slave Interface 256 x 8 bits CIO 0 2 ROM IC 4'096 x 22 bits Slave Interface CIO 1 CIO 2 TS Calibration Timer Timer 1 Timer 2 8 bits / ¼ Hz 8 bits / 32 Hz 8 bits / 1'024 Hz 4-bit Parallel Interface CIO 3 CIO 4 Reset Controller En Prescaler POR Wake-up Logic & Prescaler with 16 kHz RC Oscillator Interrupt Controller 18 stages EEPROM Controller WD 8 x 8 bits Test Logic TCK 5. CIO 5 CIO 6 CIO 7 EM6420 Configuration Inputs IC & Communication Controller Configuration TIC Figure 4-1 : 8-bit Direct Output Interface CIS 0 CIS 1 CIO 8 CIS 2 EM6420 Block Diagram PAD DESCRIPTION PAD Number Name Type Description Note Negative power supply, bulk Internal reference potential (ground) VSS Supply 2 CBL Analog Charge pump Booster Capacitor connection Low voltage side 3 CBH Analog Charge pump Booster Capacitor connection High voltage side 1 4 VCP Supply Unregulated Charge Pump output voltage, capacitor connection 5 VDDA Supply Regulated Analog supply voltage, capacitor connection 6 S15 Analog Touch Screen Sensor 15 connection Pull-down when not selected – See Note 3 7 S11 Analog Touch Screen Sensor 11 connection Pull-down when not selected – See Note 3 8 S14 Analog Touch Screen Sensor 14 connection Pull-down when not selected – See Note 3 9 S10 Analog Touch Screen Sensor 10 connection Pull-down when not selected – See Note 3 10 S7 Analog Touch Screen Sensor 7 connection Pull-down when not selected – See Note 3 Table 5-1 : Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 EM6420 pad description 7 www.emmicroelectronic.com EM6420 PAD Number Name Type Description Note 11 S6 Analog Touch Screen Sensor 6 connection Pull-down when not selected – See Note 3 12 S5 Analog Touch Screen Sensor 5 connection Pull-down when not selected – See Note 3 13 S4 Analog Touch Screen Sensor 4 connection Pull-down when not selected – See Note 3 14 S9 Analog Touch Screen Sensor 9 connection Pull-down when not selected – See Note 3 15 S13 Analog Touch Screen Sensor 13 connection Pull-down when not selected – See Note 3 16 S3 Analog Touch Screen Sensor 3 connection Pull-down when not selected – See Note 3 17 S12 Analog Touch Screen Sensor 12 connection Pull-down when not selected – See Note 3 18 S2 Analog Touch Screen Sensor 2 connection Pull-down when not selected – See Note 3 19 S8 Analog Touch Screen Sensor 8 connection Pull-down when not selected – See Note 3 20 S1 Analog Touch Screen Sensor 1 connection Pull-down when not selected – See Note 3 21 S0 Analog Touch Screen Sensor 0 connection Pull-down when not selected 22 TIC Input Factory – Reserved IC Test input Pull-down – See Note 1 23 TCK Input Factory – Reserved IC Test ClocK input Pull-down – See Note 1 24 LSV Input Low Supply Voltage selection input 25 IRQ Output Interrupt Request Output 26 CI8 Input Communication Controller Input 8 27 CIO7 Bidir Communication Controller IO 7 See Note 2 28 CIO6 Bidir Communication Controller IO 6 See Note 2 29 CIO5 Bidir Communication Controller IO 5 See Note 2 30 CIO4 Bidir Communication Controller IO 4 See Note 2 31 En Input IC Enable input 32 VDD Supply Positive power supply 33 CIO3 Bidir Communication Controller IO 3 See Note 2 34 CIO2 Bidir Communication Controller IO 2 See Note 2 35 CIO1 Bidir Communication Controller IO 1 See Note 2 36 CIO0 Bidir Communication Controller IO 0 See Note 2 37 CIS2 Input Communication Interface Selector input 2 38 CIS1 Input Communication Interface Selector input 1 39 CIS0 Input Communication Interface Selector input 0 40 VDDD Supply Regulated Digital supply voltage, capacitor connection 41 VDD Supply Positive power supply Push-pull or open-drain with internal pull-up resistor Note 1 : Connect this pad to VSS for better ESD protection in customer application Note 2 : Depending on selected communication interface, pad type may be either Input, Output or Bidirectional Note 3 : This pin must be left unconnected when not used Table 5-2 : Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 EM6420 pad description (cont’d) 8 www.emmicroelectronic.com EM6420 6. ELECTRICAL SPECIFICATIONS 6.1 ABSOLUTE MAXIMUM RATINGS Parameter Conditions Storage Temperature Supply Voltage Symbol Min Max Units TStore -40 125 °C VDD -0.2 4.6 V VMAX VSS – 0.2 VDD + 0.2 V VSS = 0 V Voltage on any pin Stresses above these listed maximum ratings may cause permanent damage to the device. Exposure beyond specified electrical characteristics may affect device reliability or cause malfunction. 6.2 HANDLING PROCEDURES This device has built-in protection against high static voltages or electric fields; however, anti-static precautions should be taken as for any other CMOS integrated circuit. Unless otherwise specified, proper operation can only occur when all terminal voltages are kept within the supply voltage range. 6.3 SUPPLY VOLTAGE CONFIGURATIONS The EM6420 is supplied by a single external power supply between VDD and VSS (Ground). A voltage multiplier and two built-in voltage regulators provide supply voltages VDDD for the internal logic and VDDA for the analog Touch Screen blocks as well as for the system clock RC oscillator. These two regulator outputs are connected to the VDDD and VDDA pads respectively, through internal resistors RVDDD and RVDDA. Together with external capacitors CVDDD and CVDDA, these internal resistors implement a low pass filter function to protect the internal circuit against parasitic over and under voltages. When used, the voltage multiplier, clocked by the wake-up RC oscillator, needs an external booster capacitor CB (typ. 47 nF) to double the input voltage and an external buffer capacitor CVCP to smooth the newly generated voltage VCP. Recommended values for the external capacitors CVDDD, CVDDA and CVCP are 100 nF, 22 nF and 100 nF. The power supply configuration depends on the selected supply voltage range (LSV input state). When the LSV input is connected to VDD, the low supply voltage range is selected. The voltage regulator VDDD is disabled (output tri-stated) to avoid an additional dropout voltage between VDD and VDDD supply voltages. In that case, the internal logic is supplied directly by VDD. The voltage multiplier is enabled and the generated voltage VCP supplies the voltage regulator VDDA, the Touch Screen sensor pads as well as several power pads. When the LSV input is connected to VSS, the high supply voltage range is selected. The internal logic is supplied by the voltage regulator VDDD to reduce overall power consumption. The voltage multiplier is disabled (output tri-stated) and the voltage regulator VDDA is supplied directly by VDD. Depending on the selected supply voltage range, 3 or 4 decoupling capacitors are required for the entire functionality of the EM6420 from -40 to + 85°C. Refer to the schematics below for proper mode of operation. In high supply voltage range (LSV is deasserted), connect: • a 100nF decoupling capacitor to VDDD • a 100nF decoupling capacitor to VDD • a 22nF decoupling capacitor to VDDA Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 9 www.emmicroelectronic.com EM6420 Legend Powered by VDD VDD Powered by VDDA Powered by VCP EM6420 VDD Powered by VDDD POR RVDDD VDDD Ref VDDD VDDD Buffer CVDDD CVDD En_VDDD LSV En_CK WU Power Configuration Logic En Wake-Up RC Oscillator CKWU EM6420 Logic V DD RVCP En_VCP VCP En_VDDA CBH Voltage Multiplier RVDDA VDDA Ref VDDA VDDA Buffer CVDDA CBL VSS EM6420 Analog S1 5 ... S0 Figure 6-1: EM6420 power supply configuration when the high voltage supply range is selected In low supply voltage range (LSV is asserted), connect: • a 47nF capacitor to pins CBH and CBL • a 100nF decoupling capacitor to VCP • a 100nF decoupling capacitor to VDD • a 22nF decoupling capacitor to VDDA Legend Powered by VDD VDD Powered by VCP Powered by VDDA EM6420 VDD Powered by VDDD V DD POR RVDDD VDDD Ref VDDD VDDD Buffer En_VDDD LSV CVDD En_CK WU Power Configuration Logic En Wake-Up RC Oscillator CKWU EM6420 Logic RVCP En_VCP VCP En_VDDA CVCP CBH Voltage Multiplier RVDDA VDDA Ref CB VDDA VDDA Buffer CVDDA CBL VSS EM6420 Analog S1 5 ... S0 Figure 6-2: EM6420 power supply configuration when the low voltage supply range is selected Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 10 www.emmicroelectronic.com EM6420 High supply voltage range configuration Low supply voltage range configuration S0 En S0 En S1 IRQ S1 IRQ S2 S3 CIO0 S4 CIO1 EM6420 S12 EM6420 S12 CIS0 CIS1 S14 CIS1 S14 CIS2 S15 CIS2 S15 TCK CBH TCK TIC TIC CBL V DD V DD 100 nF S11 CI8 S13 CIS0 CVDD S10 CIO7 S11 CI8 S9 CIO6 S10 CIO7 S8 CIO5 S9 CIO6 S7 CIO4 S8 CIO5 S6 CIO3 S7 CIO4 S5 CIO2 S6 CIO3 S4 CIO1 S5 CIO2 S2 S3 CIO0 VDD VCP LSV VDDD VSS VDDA S13 CBH CB 47 nF CBL V DD VDD VCP LSV VDDD VSS VDDA CVCP V DD 100 nF CVDDD CVDD 100 nF 100 nF CVDDA Figure 6-3 : CVDDA 22 nF 22 nF EM6420 simplified schematic of both supply voltage configurations 6.4 STANDARD OPERATING CONDITIONS The EM6420 can be used in two different modes according to customer application requirements: Low Power Mode or Ultra Low Power Mode (see § 8.3.3). In Low Power Mode, the EM6420 device remains always in Active Mode, i.e. during the scans of the sensors and also between them. The Touch Screen interface settings are internally chosen in order to minimize the current consumption. Furthermore, the communication between the host microcontroller and the EM6420 is more efficient than in Ultra low Power Mode. The EM6420 is indeed always active and so it takes less time to reply to a received command. In Ultra Low Power Mode, the EM6420 device remains in Active Mode only during the scans of the sensors and goes in Sleep Mode between them. The Touch Screen interface settings are internally chosen in order to scan as fast as possible the sensors, thus shortening as much as possible the time the EM6420 device remains in Active Mode. Furthermore, receiving a command while in Sleep Mode may slow down the communication between the host microcontroller and the EM6420, as it has first to return in Active Mode before preparing and sending the reply. But when this mode is selected, it reduces the EM6420 power consumption with full functionality to the minimum (see typical values above). If the Touch Screen interface has to be switched off for a long time, it is strongly recommended to put the EM6420 in Disable Mode by putting the En input to VSS instead of simply sending a stopTS command (see § 8.3.2). In this case, the current consumption is reduced to a few nA, but the EM6420 loses the application parameters and the host microcontroller must send them again next time the En input is set to VDD. Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 11 www.emmicroelectronic.com EM6420 Parameter Conditions Symbol Min Operating temperature TOp Low supply voltage range VDDL High supply voltage range VDDH Reference terminal VSS Typ. Max Units -40 85 °C 1.2 2.0 V 2.2 3.6 V 0 V Regulated voltage VDDD capacitor CVDDD Regulated voltage VDDA capacitor CVDDA 22 nF Unregulated voltage VCP buffer capacitor CVCP 100 nF CB 47 nF Voltage multiplier booster capacitor 100 470 nF 6.5 DC CHARACTERISTICS – POWER SUPPLY Conditions unless otherwise specified : VDD = 3.0 V, T = 25°C Parameter Conditions Supply voltage Disable mode current consumption T = -40 to +85°C 3 En input connected to VSS Sleep mode current consumption Active mode current consumption Touch Screen OFF Symbol Min Typ. Max Units VDD 2.2 3.0 3.6 V IDD_Dis 2 10 nA IDD_Slp 470 580 nA IDD_RUN 7.5 9.5 µA Conditions unless otherwise specified : VDD = 1.5 V, T = 25°C Parameter Conditions Supply voltage Disable mode current consumption T = -40 to +85°C 4 En input connected to VSS Sleep mode current consumption Active mode current consumption Touch Screen OFF Symbol Min Typ. Max Units VDD 1.2 1.5 2.0 V IDD_Dis 2 10 nA IDD_Slp 380 530 nA IDD_RUN 12.0 16.5 µA 6.6 POR Conditions unless otherwise specified : VDD = 1.5 V, T = 25°C Parameter Symbol Min Typ. Max Units High threshold voltage VIH_POR 0.75 0.90 1.10 V Threshold voltage hysteresis VHys_POR 50 110 mV 3 This value is guaranteed by design 4 This value is guaranteed by design Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 Conditions 12 www.emmicroelectronic.com EM6420 6.7 TOUCH SCREEN INTERFACE Conditions unless otherwise specified : VDD = 3.0 V or VDD = 1.5 V, T = 25°C Parameter Conditions Symbol Min Typ. TS_RCap = 00H Reference capacitor Max Units 0.5 pF 31.5 pF 0.5 pF CR TS_RCap = 3FH ∆CR Reference capacitor increment ∆TS_RCap = 1 Pad Sx input current Pull-down activated, analog switch turned OFF VIN = 0.3 V IIN_SPdON 100 180 260 µA Symbol Min Typ. Max Units Low level input voltage VIL_CIS VSS 0.3 • VDD V High level input voltage VIH_CIS 0.7 • VDD VDD V IIn_CIS -100 100 nA Symbol Min Max Units Low level input voltage VIL_En VSS 0.7 V High level input voltage VIH_En 2.2 VDD V Schmitt trigger hysteresis VHys_En 6.8 INPUT PADS CISX, CI8 AND LSV Conditions unless otherwise specified : VDD = 3.0 V or VDD = 1.5 V, T = 25°C Parameter Static input current Conditions VIN = VSS … VDD 6.9 INPUT PAD EN Conditions unless otherwise specified : VDD = 3.0 V, T = 25°C Parameter Static input current Conditions IIn_En VIN = VSS … VDD Min filtered glitches width Typ. 0.8 -100 tFGl_En Valid reset pulse width (En = VSS) tEn 50 Symbol Min Low level input voltage VIL_En High level input voltage VIH_En Schmitt trigger hysteresis VHys_En V 100 nA 10 µs µs Conditions unless otherwise specified : VDD = 1.5 V, T = 25°C Parameter Static input current Conditions IIn_En VIN = VSS … VDD Min filtered glitches width Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 Max Units VSS 0.4 V 1.1 VDD V 0.2 -100 tFGl_En Valid reset pulse width (En = VSS) tEn 13 Typ. 50 V 100 nA 10 µs µs www.emmicroelectronic.com EM6420 6.10 OUTPUT PAD IRQ Conditions unless otherwise specified : VDD = 3.0 V, T = 25°C Parameter Conditions Symbol Min Low level output current VOUT = 0.3 V IOL_IRQ 3.0 Push-pull configuration VOUT = VDD – 0.3 V IOH_IRQP Open drain with internal pullup configuration VOUT = VSS IOH_IRQQ High level output current Internal pull-up resistance Typ. Units mA -140 RPU_IRQ Max -3.0 mA -75 µA 30 kΩ Conditions unless otherwise specified : VDD = 1.5 V, T = 25°C Parameter Conditions Symbol Min Low level output current VOUT = 0.3 V IOL_IRQ 1.6 Push-pull configuration VOUT = VDD – 0.3 V IOH_IRQP Open drain with internal pullup configuration VOUT = VSS IOH_IRQQ High level output current Internal pull-up resistance Typ. Units mA -75 RPU_IRQ Max -1.6 mA -35 µA 30 kΩ 6.11 BIDIRECTIONAL PADS CIO2 … CIO7 Conditions unless otherwise specified : VDD = 3.0 V, T = 25°C Parameter Conditions Symbol Min Low level output current VOUT = 0.3 V IOL_CIO 3.0 High level output current VOUT = VDD – 0.3 V IOH_CIO Typ. Max Units mA -3 mA Low level input voltage VIL_CIO VSS 0.3 • VDD V High level input voltage VIH_CIO 0.7 • VDD VDD V IIN_CIO -100 100 nA Max Units Static input current VIN = VSS … VDD Conditions unless otherwise specified : VDD = 1.5 V, T = 25°C Parameter Conditions Symbol Min Low level output current VOUT = 0.3 V IOL_CIO 1.6 High level output current VOUT = VDD – 0.3 V IOH_CIO Typ. mA -1.6 mA Low level input voltage VIL_CIO VSS 0.3 • VDD V High level input voltage VIH_CIO 0.7 • VDD VDD V IIN_CIO -100 100 nA Static input current Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 VIN = VSS … VDD 14 www.emmicroelectronic.com EM6420 6.12 BIDIRECTIONAL PADS CIO0 AND CIO1 Conditions unless otherwise specified : VDD = 3.0 V, T = 25°C Parameter Conditions Symbol Min Low level output current VOUT = 0.3 V IOL_I2C 3.0 Push-pull configuration VOUT = VDD – 0.3 V High level output current Typ. Max Units mA IOH_I2CP -3.0 mA Open drain with internal weak pull-up configuration VOUT = VSS IOH_I2CWR -120 -50 µA Open drain with internal strong pull-up configuration VOUT = VSS IOH_I2CSR -200 -110 µA Internal weak pull-up resistance RI2C_W 40 kΩ Internal strong pull-up resistance RI2C_S 20 kΩ Low level input voltage VIL_I2C VSS 0.3 • VDD V High level input voltage VIH_I2C 0.7 • VDD VDD V IIN_I2C -100 100 nA VHys_I2C 0.05 • VDD Static input current Open drain with no internal pull-up configuration VIN = VSS … VDD Schmitt trigger hysteresis V Conditions unless otherwise specified : VDD = 1.5 V, T = 25°C Parameter Conditions Symbol Min Low level output current VOUT = 0.3 V IOL_I2C 1.6 Push-pull configuration VOUT = VDD – 0.3 V High level output current Typ. Max Units mA IOH_I2CP -1.6 mA Open drain with internal weak pull-up configuration VOUT = VSS IOH_I2CWR -60 -25 µA Open drain with internal strong pull-up configuration VOUT = VSS IOH_I2CSR -100 -55 µA Internal weak pull-up resistance RI2C_W 40 kΩ Internal strong pull-up resistance RI2C_S 20 kΩ Low level input voltage VIL_I2C VSS 0.3 • VDD V High level input voltage VIH_I2C 0.7 • VDD VDD V IIN_I2C -100 100 nA VHys_I2C 0.1 • VDD Static input current Open drain with no internal pull-up configuration VIN = VSS … VDD Schmitt trigger hysteresis Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 15 V www.emmicroelectronic.com EM6420 7. TIMING SPECIFICATIONS 7.1 STANDARD OPERATING CONDITIONS Parameter Symbol Min Operating Temperature TOp -40 Low Supply Voltage Range VDDL 1.2 High Supply Voltage Range VDDH 2.2 Reference terminal VSS Typ. Max Units 85 °C 1.5 2.0 V 3.0 3.6 V 0 V 7.2 COMMUNICATION INTERFACE Parameter Conditions Symbol Min Typ. 8-bit Direct Output Interface selected Communication interface start-up time Max Units 70 ms 10 ms 150 µs Max Units 150 µs tCI_St SPI, I2C or Parallel Interface selected IRQ start-up pulse width tIRQ_StPW 100 Symbol Min tIRQ_PW 100 7.3 8-BIT DIRECT OUTPUT INTERFACE Parameter Conditions IRQ pulse width Typ. 7.4 SLAVE I2C INTERFACE S P Sr SDA D6 ... D 0 D7 ACK D 7 ... D 0 tI2 C_ DSU t STASU t I2 C_ F t STAH t SCL H t I2 C_ R t I2 C_ R tI2 C_ DH t STAH t I2 C_ F S ACK tBF tSTOSU SCL tSCL L Figure 7-1: I2C interface timings Conditions unless otherwise specified : VDD = 3.0 V or VDD = 1.5 V, T = 25°C Parameter Symbol Min SCL clock frequency fSCL 0 Hold time (repeated) START condition. tSTAH 0.6 µs Low period of the SCL clock tSCLL 1.3 µs High period of the SCL clock tSCLH 0.6 µs Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 Conditions 16 Typ. Max Units 400 kHz www.emmicroelectronic.com EM6420 Conditions unless otherwise specified : VDD = 3.0 V or VDD = 1.5 V, T = 25°C Parameter Conditions Symbol Min Setup time for a repeated START condition tSTASU 0.6 Data hold time tI2C_DH 0 Data setup time tI2C_DSU 100 Rise time of both SDA and SCL signals tI2C_R 20 + 0.1·Cb 300 ns Fall time of both SDA and SCL signals tI2C_F 20 + 0.1·Cb 300 ns Setup time for a STOP condition tSTOSU 0.6 µs tBF 1.3 µs Bus free time between a STOP and a START condition Capacitive load for each bus line Typ. Max Units µs 0.9 µs ns With internal pull-up resistors Cb 200 pF With external pull-up resistors Cb 400 pF 7.5 SLAVE SPI INTERFACE nSS tSCK2 n SS tn SSH SDO X DO7 DO0 DO6 ... DO 1 DI7 DO7 t SDO2 SRDY SDI X DI7 CK_Pol VDD VSS DO6 ... DO DO0 1 DI7 X t SDO2 SRDY DI0 DI6 ... DI 1 DI7 t SCKL t SCKH tSPI_ R tSCKH t SCKL tSPI_ F DI 6 ... DI DI 0 1 X t SPI_ DH t SPI_ Cyc tSPI_ DSU SCK SCK t n SS2 SRDY t SCK2 SRDY t SRDY2 SCK tSRDY2 SCK t SCK2 SRDY SRDY Figure 7-2 : Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 SPI Interface timings when CK_Pha input is set to VSS. 17 www.emmicroelectronic.com EM6420 nSS tSCK2 n SS tn SSH SDO X DO7 DO6 ... DO 1 DO0 DO7 t SDO2 SRDY SDI X DI7 CK_Pol VDD VSS DO6 ... DO DO0 1 X t SDO2 SRDY DI6 ... DI 1 DI0 t SCKL t SCKH tSPI_ R tSCKH t SCKL tSPI_ F DI7 DI 6 ... DI DI0 1 tSPI_ DH t SPI_ DSU SCK t SPI_ Cyc SCK t n SS2 SRDY t SCK2 SRDY t SRDY2 SCK tSRDY2 SCK t SCK2 SRDY SRDY Figure 7-3 : SPI Interface timings when CK_Pha input is set to VDD. Conditions unless otherwise specified : VDD = 3.0 V or VDD = 1.5 V, T = 25°C Parameter Conditions Symbol Operating frequency fSPI_Op Cycle time tSPI_Cyc Min Typ. Max Units 400 kHz 2.5 µs Rise time of inputs SCK, SDI and nSS tSPI_R 250 ns Fall time of inputs SCK, SDI and nSS tSPI_F 250 ns tnSS2SRDY 200 ns Delay from nSS low to SRDY high Low period of the SCK clock tSCKL 1 µs High period of the SCK clock tSCKH 1 µs Data setup time tSPI_DSU 200 ns Data hold time tSPI_DH 200 ns Delay from valid data to SRDY high tSDO2SRDY Delay from SRDY high to first SCK edge tSRDY2SCK Delay from last SCK edge to SRDY low tSCK2SRDY 200 ns Delay from last SCK edge to nSS high tSCK2nSS 200 ns nSS high time (Bus free time between communication frames) tnSSH Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 18 200 200 2 ns ns µs www.emmicroelectronic.com EM6420 7.6 SLAVE 4-BIT PARALLEL INTERFACE CE t CS2 CE tCEL D 3 ... D0 XH DI7 ...DI 4 DI3 ...DI 0 t Pa r_ DH t Pa r_ DSU XH DO3 ...DO0 tRW2 D DO7 ...DO 4 DO3 ...DO 0 t Pa r_ Cyc tD2 SRDY t CSH XH DI7 ...DI 4 tPa r_ R DI3 ...DI 0 XH tPa r_ F t RW2 D CS t SRDY2 CS t CSL tCS2 RW tRW2 CS t CS2 RW RD / nWR t CE2 SRDY t CS2 SRDY t SRDY2 CS tCS2 SRDY SRDY Figure 7-4 : Parallel Interface timings Conditions unless otherwise specified : VDD = 3.0 V or VDD = 1.5 V, T = 25°C Parameter Conditions Symbol Min Typ. Max Units 400 kHz Operating frequency fPar_Op Cycle time tPar_Cyc Rise time of inputs CE, CS, RD / nWR and DX tPar_R 250 ns Fall time of inputs CE, CS, RD / nWR and DX tPar_F 250 ns Delay from CE high to SRDY high tCE2SRDY 200 ns Time interval between CS strobes tCSL 1 µs CS strobe width tCSH 1 µs Data setup time tPar_DSU 200 ns Data hold time tPar_DH 200 ns Delay from valid data to SRDY high tD2SRDY Delay from SRDY high to CS strobe tSRDY2CS Delay from CS strobe to SRDY low tCS2SRDY 200 ns Delay from RD / nWR low to valid data tRW2D 200 ns Delay from RD / nWR high to CS strobe tRW2CS 200 ns Delay from CS strobe to RD / nWR low tCS2RW 200 ns Delay from CS strobe to CE low tCS2CE 200 ns tCEL 2 µs CE low time (Bus free time between communication frames) Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 19 2.5 µs 200 200 ns ns www.emmicroelectronic.com EM6420 8. EM6420 TO HOST CONTROLLER COMMUNICATION 8.1 INTRODUCTION The EM6420 can communicate with a host processor through several communication interfaces, mainly to receive application parameters, to signal sensors activity or to send EM6420 status / error flags. Only one communication interface can be active at a time, as they share the same EM6420 IO pads CIO7 … CIO0 and input pad CI8. During a communication, the host processor is always considered as the master device and the EM6420 as the slave one. Thus, the EM6420 may never initiate a communication. However, by asserting its output pad IRQ, the EM6420 can signal to the host processor that a predefined condition or an error occurred and that a communication may be initiated, normally by a getStatus command. Host Microcontroller IO IRQ COM port IO En EM6420 EM6420 IRQ IRQ COM port En COM port S0 - S15 Connexion to Touch Screen Sensors En COMCfg port Figure 8-1 : S0 - S15 Connexion to Touch Screen Sensors COMCfg port Multi EM6420 configuration In applications where several EM6420 are used, the open-drain with internal pull-up resistor configuration must be selected for IRQ output pads, to allow connecting all these output pads to a unique host IRQ input (see Figure 8-1). irq_pp VDD VDD irqo RPU_ IRQ IRQ irq_stat Figure 8-2 : Configuration of EM6420 IRQ output pad In this case, all IRQ output pads should be asserted by default (wired-OR), and each EM6420 can signal to the host processor that a communication may be initiated by deasserting its output pad IRQ. Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 20 www.emmicroelectronic.com EM6420 8.2 EM6420 COMMUNICATION INTERFACES Active EM6420 communication interface is selected by input pads CIS2 … CIS0 state, according to the Table 8-1. CIS2 CIS1 CIS0 0 0 0 Slave I2C Interface 0 0 1 Slave 4-bit Parallel Interface 0 1 X Slave SPI Interface 1 X X 8-bit Direct Output Interface Table 8-1 : Active Communication Interface Communication interface selection As input pads CIS2 … CIS0 do not include pull resistors, they must be connected either to VSS or VDD in customer application. Selecting a communication interface will directly define the functionality of communication input pad CI8 and IO pads CIO7 … CIO0, thus configuring IO pads either as input, output or bidirectional pad. 8.2.1 Slave I2C Interface 2 When slave I C interface is selected, communication pads CI8 and CIO7 … CIO0 are 2 2 configured for specific I C functions or define I C interface options, according to the Table 8-2: PAD Name Alternate name Type Specific function or defined option for slave I2C interface CIO0 SCL Bidir I2C Serial Clock CIO1 SDA Bidir I2C Serial Data CIO2 EN_IWPU Input Enable Internal Weak Pull-Up resistors CIO3 EN_ISPU Input Enable Internal Strong Pull-Up resistors CIO7 … CIO4 A3 ... A0 Input Low 4-bit I2C Address. Default high 3-bits I2C address are 100B CI8 IRQ_Pol Input IRQ Polarity Table 8-2 : 2 2 Defined I C options and specific functions for communication pads CI8 and CIO7 … CIO0 when slave I C interface is selected 2 2 This I C interface fulfills the I C specification (see [1] “The I2C-Bus Specification – Version 2.1”, Philips Semiconductors, January 2000) with the following restrictions: • • • • 5 Only Standard-mode and Fast-mode are supported. Thus, the maximum clock frequency is 400 kHz. Only standard 7-bit addressing is supported. The default values of the higher three bits 5 are 100B while the lower 4 bits are defined by A3…A0 input pads. General Calls are ignored. 2 Each I C bidir pad has a weak and a strong internal pull-up resistor. They can be enabled by connecting the En_IWPU and / or EN_ISPU input pads to VDD. However, these internal pull-up resistors have been designed to minimize power consumption. As such, they can only drive capacitive bus loads up to 200 pF, even when both pull-up 2 resistors are simultaneously enabled. For higher capacitive bus loads, external I C pullup resistors must be added. Please contact EM Microelectronic-Marin SA for setting other values to the three higher address bits Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 21 www.emmicroelectronic.com EM6420 The IRQ_Pol input defines the polarity of the IRQ output: • • 8.2.2 The positive IRQ polarity is selected when the IRQ_Pol input is connected to VDD, and a rising edge is generated when the EM6420 asserts its IRQ output. The negative IRQ polarity is selected when the IRQ_Pol input is connected to VSS, and a falling edge is generated when the EM6420 asserts its IRQ output. Slave SPI Interface When slave SPI interface is selected, communication pads CI8 and CIO7 … CIO0 are configured for specific SPI functions or define SPI interface options, according to the Table 8-3: PAD Name Alternate name Type Specific function or defined option for slave SPI interface CIO0 SCK Input SPI Serial ClocK CIO1 SDI Input SPI Serial Data Input CIO2 SDO Output CIO3 nSS Input SPI Slave Select (active low) CIO4 SRDY Output SPI Slave ReaDY (see below) CIO5 CK_Pol Input SPI ClocK Polarity (see below) CIO6 CK_Pha Input SPI ClocK Phase (see below) CIO7 MSB_First Input SPI data are sent MSB First (see below) CI8 IRQ_Pol Input IRQ Polarity (see below) Table 8-3 : SPI Serial Data Output Defined SPI options and specific functions for communication pads CI8 and CIO7 … CIO0 when slave SPI interface is selected This 4-wire SPI interface allows full-duplex, synchronous, serial communication between the host and the EM6420. The clock signal SCK generated by the host synchronizes data transmission. The nSS input is the control signal used to enable the EM6420 SPI interface. When set to VDD, the SDO and the SRDY outputs are tri-stated, thus allowing another EM6420 to take control of these lines in applications where several devices are used (see Figure 8-3). Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 22 www.emmicroelectronic.com EM6420 Host Microcontroller IO SCK SDO SDI IO IO IO IO IRQ SCK MOSI MISO SRDY nSS 0 nSS 1 En EM6420 EM6420 IRQ IRQ SCK SCK SDI SDI SDO SDO SRDY SRDY nSS nSS Connexion to Touch Screen Sensors S0 - S15 En COMCfg port Connexion to Touch Screen Sensors S0 - S15 En COMCfg port Figure 8-3: Multi EM6420 configuration using the SPI interface To accommodate the different serial communication requirements of hosts, the EM6420 is able to control the timing relationship between the serial clock SCK and the transmitted data on SDO output. CK_Pol CK_Pha nSS VSS VSS SCK (00) VDD VSS SCK (10) VSS VDD SCK (01) VDD VDD SCK (11) SDI / SDO X D7 D6 D5 D4 D3 D2 D1 D0 X Capture Edge Figure 8-4: Timing relationship between the serial clock SCK and the transmitted data The CK_Pol input indicates to the EM6420 the polarity of the SCK clock signal between transmissions: • • When set to VSS, the SCK clock signal is set to VSS between transmissions. When set to VDD, the SCK clock signal is set to VDD between transmissions. The CK_Pha input defines which clock edge latches the data: • • When set to VSS, the data on SDI input is latched at the first SCK clock edge. Data on SDI input and SDO output must change at the second SCK clock edge. When set to VDD, the data on SDI input is latched at the second SCK clock edge. Data on SDI input and SDO output must change at the first SCK clock edge. The SRDY output indicates to the host that the EM6420 is ready to send and receive a data byte. The host must always check that SRDY is set to VDD before generating the eight clocks needed to transfer a data byte. Data byte is sent MSB first when the MSB_First input is set to VDD and LSB first otherwise. The IRQ_Pol input defines the polarity of the IRQ output: Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 23 www.emmicroelectronic.com EM6420 • The positive IRQ polarity is selected when the IRQ_Pol input is connected to VDD, and a rising edge is generated when the EM6420 asserts its IRQ output. The negative IRQ polarity is selected when the IRQ_Pol input is connected to VSS, and a falling edge is generated when the EM6420 asserts its IRQ output. • 8.2.3 Slave 4-bit Parallel Interface When slave 4-bit parallel interface is selected, communication pads CI8 and CIO7 … CIO0 are configured for specific 4-bit parallel functions and define IRQ output pad polarity, according to the Table 8-4: PAD Name Alternate name Type Specific function for slave 4-bit parallel interface CIO3 … CIO0 D3 … D0 Bidir 4-bit Data bus CIO4 CE Input Chip Enable control signal CIO5 RD / nWR Input ReaD / not WRite control signal CIO6 CS Input Chip Select control signal CIO7 SRDY Output Slave ReaDY CI8 IRQ_Pol Input IRQ Polarity Table 8-4 : Defined IRQ polarity and specific functions for communication pads CI8 and CIO7 … CIO0 when slave 4-bit parallel interface is selected This parallel interface allows fast bidirectional and synchronous communication between the host and the EM6420. The CE input is the control signal used to enable the EM6420 parallel interface. When set to VSS, the data lines D3 ... D0 as well as the SRDY output are tri-stated, thus allowing another EM6420 to take control of these lines in applications where several devices are used. When the CE input is set to VDD, the EM6420 drives its SRDY output and also the data lines D3 … D0 if the RD / nWR input is set to VDD too. The data lines D3 … D0 are driven by the host when the RD / nWR control signal is set to VSS. Host Microcontroller IO D[3..0] RD / nWR CS IO IO IO IO IRQ D[3..0] RD / nWR CS SRDY CE0 CE1 En EM6420 EM6420 IRQ IRQ D[3..0] D[3..0] RD / nWR RD / nWR CS CS SRDY SRDY CE En CE S0 - S15 Connexion to Touch Screen Sensors COMCfg port S0 - S15 En Connexion to Touch Screen Sensors COMCfg port Figure 8-5: Multi EM6420 configuration using the 4-bit parallel interface Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 24 www.emmicroelectronic.com EM6420 The CS input is the control signal used to effectively read or write a data nibble on the data bus. Data lines D3 … D0 can only change at the CS rising edge, and they are sampled at the CS falling edge. The SRDY output indicates to the host that the EM6420 is ready to send or receive a data byte. The host must always check that SRDY is set to VDD before generating the two CS strobes needed to transfer a data byte. Data byte is sent high nibble first. DIx Command c ode rec eiv ed by the EM6420 DOx Firs t data by te returned by the EM6420 DOx Third data by te returned by the EM6420 DOx Sec ond data by te returned by the EM6420 DOx Fourth data by te returned by the EM6420 Capture Edge CE D 3 ... D0 XH DI7 ...DI 4 DI3 ...DI 0 XH DO3 ...DO 0 DO7 ...DO 4 DO3 ...DO 0 DO7 ...DO 4 DO3 ...DO 0 DO7 ...DO 4 DO3 ...DO 0 DO7 ...DO 4 DO3 ...DO 0 CS RD / nWR SRDY Figure 8-6: Typical data transfer using the parallel 4-bit interface. The IRQ_Pol input defines the polarity of the IRQ output: • • 8.2.4 The positive IRQ polarity is selected when the IRQ_Pol input is connected to VDD, and a rising edge is generated when the EM6420 asserts its IRQ output. The negative IRQ polarity is selected when the IRQ_Pol input is connected to VSS, and a falling edge is generated when the EM6420 asserts its IRQ output. 8-bit Direct Output Interface When 8-bit direct output interface is selected, communication pads CI8 and CIO7 … CIO0 are configured for specific 8-bit direct output functions and define Touch Screen IRQ condition, according to the Table 8-5: PAD Name Alternate name Type CIO7 … CIO0 SStO7 … SStO0 Output CI8 MAS Input Specific function for 8-bit direct output interface Sensors Status Output port Touch Screen Most Activated Sensor feature Table 8-5 : Touch Screen feature and specific functions for communication pads CI8 and CIO7 … CIO0 when 8-bit direct output interface is selected Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 25 www.emmicroelectronic.com EM6420 In this configuration, the EM6420 can only provide sensors status on an 8-bit output port. As no application parameters can be received from the host processor, the EM6420 defines itself the number of sensors to be scanned (up to 8 sensors) while the Touch Screen scan frequency is defined from configuration inputs CIS0 and CIS1, according to Table 8-6. Therefore, the EM6420 may also be used in a standalone configuration, i.e. without any host processor connection. CIS1 CIS0 Touch Screen scan frequency 0 0 2 Hz 0 1 8 Hz 1 0 32 Hz 1 1 128 Hz Table 8-6 : Touch Screen scan frequency when 8-bit Direct Output interface is selected (Standalone configuration) When 8-bit direct output interface is selected, the Touch Screen interface is always ON. Activating a sensor will directly asserts its corresponding bit on output port SStO7 … SStO0. When input pad MAS is connected to VDD, only the bit corresponding to the most activated sensor is asserted, even if other sensors are also active. By default, the output port polarity is positive 6, i.e. the SStOx outputs are asserted when they are set to VDD. A pulse of at least 100 µs is generated on the IRQ output every time a Touch Screen IRQ condition occurred. By default, the pulse polarity is negative and the open-drain with internal pull-up resistor configuration is selected by embedded software for the IRQ output pad 7. t IRQ_ PW > 100 µs tIRQ_ PW > 100 µs SStO 7 ... SStO0 IRQ Figure 8-7: Default IRQ output pad timing when 8-bit direct output is selected 6 Please contact EM Microelectronic-Marin SA to change the output port polarity from positive to negative, in order to have the SStOx outputs set to VSS when they are asserted 7 Please contact EM Microelectronic-Marin SA to change the IRQ polarity from negative to positive and to select the push-pull instead of the open-drain configuration for the IRQ output pad Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 26 www.emmicroelectronic.com EM6420 8.2.5 Communication interface initialization. At start-up, the EM6420 can determine which communication interface is active. It then sets the required communication options according to the communication pads CI8 and CIO7 … CIO0 state. Finally, the EM6420 IRQ output pad is activated and special code 18H is returned in the next getStatus command, thus signaling to the host controller that it is ready to accept communication frames. See Table 8-16 on page 39 for a complete list of the possible special codes. When the positive IRQ polarity is used, the push-pull configuration is selected by the embedded software for the IRQ output pad and the timings shown in Figure 8-8 are generated at startup. Output pad IRQ is deasserted when returning special code 18 Hat the first getStatus command Communication interface is configured EM6420 start-up IRQ I 2C, SPI or 4-bit parallel interface selected IRQ 8-bit Direct Output interface selected t IRQ_ PW > 100 µs t CI_ St Figure 8-8 : IRQ output startup timings when positive IRQ polarity is selected by embedded software When the negative IRQ polarity is used, the open-drain with internal pull-up resistor configuration is selected by the embedded software for the IRQ output pad and the timings shown in Figure 8-9 are generated at startup. Communication interface is configured Output pad IRQ is deasserted when returning special code 18H at the first getStatus command EM6420 start-up IRQ I2C, SPI or 4-bit parallel interface selected IRQ 8-bit Direct Output interface selected tIRQ_StPW > 100 µs tIRQ_PW > 100 µs t CI_St Figure 8-9 : IRQ output pad start-up timings when negative IRQ polarity is selected Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 27 www.emmicroelectronic.com EM6420 8.3 EM6420 COMMANDS Communication commands interpreted by the EM6420 can be grouped into 3 command sets: • The first command set includes all single byte commands, as described in Table 8-7. These commands are mainly used to send a new parameter value to the EM6420. Command name Command description startTS Start the Touch Screen interface stopTS Stop the Touch Screen interface setTSMode Select the Touch Screen running features selectBaseSettings Select the base settings as the current settings selectAltSettings Select the alternate settings as the current settings setBaseScanFreq Set the Touch Screen base scan frequency setAltScanFreq Set the Touch Screen alternate scan frequency setBaseHiSensNb Set the base highest sensor number to be scanned setAltHiSensNb Set the alternate highest sensor number to be scanned setBaseIRQCond Set the base IRQ condition setAltIRQCond Set the alternate IRQ condition next Request the next data byte within a multiple data byte read sequence (SPI interface only) end End a multiple data byte read sequence (SPI interface only) Table 8-7 : EM6420 single byte command set • The second command set includes two-byte commands, as described in the following table. These commands are used to get any parameter value from the EM6420 or to send a more than 4-bit parameter value to the EM6420. Command name Command description setThreshold Set Touch Screen threshold getAppSettings Get current application settings Table 8-8 : • EM6420 two-byte command set The third command set includes multiple byte commands, as described in the following table. These commands are used to get multiple parameters from or to send multiple parameters to the EM6420, thus reducing communication traffic and overall system consumption. Command name Command description getVersion Get EM6420 HW and SW version getStatus Get EM6420 status Table 8-9 : EM6420 multiple bytes command set Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 28 www.emmicroelectronic.com EM6420 8.3.1 Command startTS This command starts the EM6420 Touch Screen interface. 0 1 0 0 1 0 1 0 0 7 14H 0 Figure 8-10 : startTS command format At power-up, the Touch Screen interface is stopped. Some settings must be defined before the Touch Screen is started, and cannot be changed later on. Therefore, the commands setTSMode, setBaseScanFreq, setBaseHiSensNb, setBaseIRQCond and setThreshold, if used, must be sent before the startTS command. Attempting to send one of these commands while the Touch Screen interface is running will cause the EM6420 to assert its IRQ output and return error code 06H. The Touch Screen base settings are checked when the Touch Screen interface is started. If they are invalid, the EM6420 asserts its IRQ output and returns error code 02H. During the Touch Screen startup, the EM6420 checks the presence of each sensor and establishes a sensor map. If the total number of sensors wasn't specified before the startTS command (with the setBaseHiSensNb command), the device scans all sixteen sensors and determines the number of sensors by itself. To be valid, the sensor map must have at least sensor 0 connected and there must be no lack between the first and the last used sensor. If the highest sensor number was specified, the following sensors will never be scanned. If the EM6420 detects a problem with the sensor map, it asserts its IRQ output and returns error code 01H. If the alternate settings are already selected before the startTS command is used, that is if the command selectAltSettings was sent before the startTS command, the EM6420 will automatically apply the alternate settings immediately after the Touch Screen startup. However, initialization of the sensors is always performed according to the base settings. Sending the startTS command while the Touch Screen interface is already running will restart it according to the base settings for initialization, and then it will use the previous selected settings. Sensors that are already activated during the Touch Screen startup procedure will not be detected until they are released and the EM6420 has had enough time to initialize them properly. 8.3.2 Command stopTS This command stops the EM6420 Touch Screen interface. 0 1 0 0 1 0 1 0 7 1 15H 0 Figure 8-11 : stopTS command format This command has no effect if the Touch Screen interface is already stopped. Stopping the Touch Screen interface allows the host to change the base settings with the commands setTSMode, setBaseScanFreq, setBaseHiSensNb, setBaseIRQCond and setThreshold. However, if some sensors are activated during the next startup procedure (initiated by the startTS command), they will not be detected by the EM6420 until they are released and the EM6420 has had enough time to initialize them properly. 8.3.3 Command setTSMode This command sets the EM6420 Touch Screen running features. 0 1 0 7 1 1 0 TSM 30H # TSM 0 Figure 8-12 : setTSMode command format Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 29 www.emmicroelectronic.com EM6420 Table 8-10 gives the mapping between the TSM bits and the selected Touch Screen running features. Bit Behavior if bit is set Behavior if bit is cleared 0 EM6420 works in Ultra Low Power mode EM6420 works in Low Power mode 1 Each sensor sensitivity is continuously optimized, taking into account actual room temperature and supply voltage Each sensor sensitivity is optimized only when the Touch Screen interface is started 2 Each sensor has its own activation threshold which is continuously adapted to sensor sensitivity All sensors have the same activation threshold which is a fixed value Table 8-10 : Mapping between the TSM bits and the Touch Screen running features The Touch Screen running features must be defined before starting the Touch Screen interface. By default, the TSM bits values are 111B when 8-bit direct output interface is 8 selected and 110B when any other communication interface is selected . Attempting to modify the Touch Screen running features while the Touch Screen interface is running will cause the EM6420 to assert its IRQ output and return the error code 06H. 8.3.4 Command selectBaseSettings This command selects the basic settings as the Touch Screen current settings. 0 1 1 1 1 0 1 0 0 7 74H 0 Figure 8-13 : selectBaseSettings command format The Touch Screen base settings can be defined by setBaseScanFreq, setBaseHiSensNb and setBaseIRQCond commands. If used, these commands must be sent before the Touch Screen interface is started. If they aren't used, default values are supplied for the base settings. At power-up, the base settings (as opposed to the alternate settings) are selected, so that this command is only needed after a selectAltSettings command, in order to switch back to the base settings. The Touch Screen base settings are checked when the Touch Screen interface is started. If they are invalid, the EM6420 asserts its IRQ output and returns error code 02H. Attempting to change the base settings while the Touch Screen interface is running will cause the EM6420 to assert its IRQ output and return error code 06H. It is possible to switch from the alternate settings to the base settings at any time, even when the Touch Screen interface is running. In that case, the base settings are applied immediately. This command has no effect if the base settings are already selected. 8.3.5 Command selectAltSettings This command selects the alternate settings as the Touch Screen current settings. 0 1 1 1 1 0 1 0 7 1 75H 0 Figure 8-14 : selectAltSettings command format The Touch Screen alternate settings are defined by setAltScanFreq, setAltHiSensNb and setAltIRQCond commands. They can be modified when the Touch Screen interface is stopped as well as when it's running even if some other alternate settings are currently active.. However, the new alternate settings will not take effect immediately after one of 8 Please contact EM Microelectronic-Marin SA to change the default values of TSM bits 1 and 2 Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 30 www.emmicroelectronic.com EM6420 these three commands. Instead, if the Touch Screen interface is running, the new alternate settings will be applied at the next occurrence of a setAltSettings command. If the Touch Screen interface is stopped and the alternate settings are already selected, they will be applied directly after the next startTS command. Each alternate parameter that has never been explicitly set through the appropriate command, when applied, will be substituted by the corresponding base settings. Therefore, toggling between base and alternate settings without having ever sent any of the three setAlt... commands won't have any effect. The validity of the new alternate settings is checked when they are applied, that is either after a selectAltSettings or a startTS command. If they are invalid, the EM6420 asserts its IRQ output and returns error code 03H. 8.3.6 Command setBaseScanFreq This command sets the basic scan frequency of Touch Screen sensors. 0 1 1 0 1 0 SF 7 50H # SF 0 Figure 8-15 : setBaseScanFreq command format Table 8-11 lists valid values for parameter SF. Note that a 64 Hz or 128 Hz scan frequency can only be used with a reduced number of sensors, i.e. 8 at 64 Hz and 4 at 128 Hz. SF Touch Screen scan frequency SF Touch Screen scan frequency 000B 1 Hz 100B 16 Hz 001B 2 Hz 101B 32 Hz 010B 4 Hz 110B 64 Hz 011B 8 Hz 111B 128 Hz Table 8-11 : Selection of Touch Screen scan frequency The setBaseScanFreq command, if used, must be sent before the Touch Screen interface is started. If the setBaseScanFreq command isn’t used, the base scan frequency is 8 Hz by default. Attempting to modify the base scan frequency while the Touch Screen interface is running will cause the EM6420 to assert its IRQ output and return error code 06H. 8.3.7 Command setAltScanFreq This command sets the alternate scan frequency of Touch Screen sensors. 1 1 0 7 0 1 0 ASF 90H # ASF 0 Figure 8-16 : setAltScanFreq command format Table 8-12 lists valid values for parameter ASF. Note that a 64 Hz or 128 Hz scan frequency can only be used with a reduced number of sensors, i.e. 8 at 64 Hz and 4 at 128 Hz. Moreover, the alternate scan frequency cannot be greater than the base scan frequency. The EM6420 will assert its IRQ output and return error code 03H if these conditions are not met when the alternate settings are applied. Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 31 www.emmicroelectronic.com EM6420 ASF Touch Screen scan frequency ASF Touch Screen scan frequency 000B 1 Hz 100B 16 Hz 001B 2 Hz 101B 32 Hz 010B 4 Hz 110B 64 Hz 011B 8 Hz 111B 128 Hz Table 8-12 : Selection of alternate Touch Screen scan frequency The alternate scan frequency can be modified at any time, even if some other Touch Screen alternate settings are already selected. However, the new alternate scan frequency will be taken into account only next time a setAltSettings command is issued. By default, if the setAltScanFreq command has never been sent, the alternate scan frequency is the same as the base scan frequency (no change in scan frequency when switching from base to alternate settings). 8.3.8 Command setBaseHiSensNb This command sets the highest sensor number to be scanned when base settings are selected. Sensors are numbered from 0 to 15. 0 1 1 0 0 HSN 7 40H # HSN 0 Figure 8-17 : setBaseHiSensNb command format Valid values for parameter HSN range from 0 to 15, allowing the host to select from one to sixteen sensors. The base highest sensor number can only be defined before the Touch Screen interface is started. Attempting to modify the base highest sensor number while the Touch Screen interface is already running will cause the EM6420 to assert its IRQ output and return error code 06H. If the base highest sensor number hasn’t been defined when the Touch Screen interface is started, the EM6420 will determine the number of connected sensors by itself. Otherwise, if the number of sensors has been defined, it will check that these sensors are effectively connected. An error in the sensor map (due to inappropriate settings or to sensors failure) will cause the EM6420 to assert its IRQ output and generate error 01H at the next startTS command. 8.3.9 Command setAltHiSensNb This command sets the alternate highest sensor number to be scanned. 1 1 0 0 7 0 ASHN 80H # AHSN 0 Figure 8-18 : setAltHiSensNb command format Valid values for parameter AHSN range from 0 to 15, allowing the host to select from one up to sixteen sensors. The alternate highest sensor number must not be greater than the highest sensor number selected in the base settings. The alternate highest sensor number can be modified at any time, even if some other alternate settings are currently being used. However, the new alternate highest sensor number will be taken into account only next time a setAltSettings command is issued. By default, if the setAltHiSensNb command has never been sent, the alternate sensor number is the same as the base sensor number (no change in number of sensors when switching from base to alternate settings). Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 32 www.emmicroelectronic.com EM6420 8.3.10 Command setBaseIRQCond This command sets the basic Touch Screen IRQ condition. 0 1 1 1 0 0 0 IC 7 60H # IC 0 Figure 8-19 : setBaseIRQCond command format Table 8-13 gives the mapping between IC parameter values and the selected Touch Screen IRQ condition. IC Touch Screen IRQ condition 00B EM6420 output pad IRQ is asserted at the end of each sensors scan 01B EM6420 output pad IRQ is asserted at the end of a sensors scan, when at least one sensor state has changed 10B EM6420 output pad IRQ is asserted at the end of a sensors scan, when either at least one sensor is active or at least one sensor state has changed 11B EM6420 output pad IRQ is asserted at the end of a sensors scan, when the most activated sensor has changed Table 8-13 : Selection of EM6420 IRQ condition The Touch Screen IRQ condition defines under which circumstances the EM6420 will assert its IRQ output to signal events happening on the Touch Screen. The IRQ output remains asserted until the new Touch Screen state is returned in response to a getStatus command. The base Touch Screen IRQ condition should be defined before starting the Touch Screen interface. Two separate default values exist when 8-bit direct output interface is selected: the default value is 11B when MAS input is asserted and 01B when MAS input is deasserted or when any other communication interface is selected 9. Attempting to modify the base IRQ condition while the Touch Screen interface is running will cause the EM6420 to assert its IRQ output and return error code 06H. 8.3.11 Command setAltIRQCond This command set the alternate Touch Screen IRQ condition. 1 1 0 7 1 0 0 0 AIC A0H # AIC 0 Figure 8-20 : setAltIRQCond command format Table 8-14 gives the mapping between AIC parameter values and the selected Touch Screen IRQ condition. When alternate settings are selected, the alternate Touch Screen IRQ condition defines under which circumstances the EM6420 will assert its IRQ output to signal events happening on the Touch Screen. The IRQ output remains asserted until the new Touch Screen state is returned in response to a getStatus command. The alternate Touch Screen IRQ condition can be modified at any time, even if some other alternate settings are currently being used. However, the new alternate IRQ condition will be taken into account only next time a setAltSettings command is issued. By default, if the setAltIRQCond command has never been sent, the alternate IRQ condition is the same as the base IRQ condition (no change in IRQ generation mode when switching from base to alternate settings). 9 Please contact EM Microelectronic-Marin SA to change the default Touch Screen IRQ condition values Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 33 www.emmicroelectronic.com EM6420 AIC Touch Screen IRQ condition 00B EM6420 output pad IRQ is asserted at the end of each sensors scan 01B EM6420 output pad IRQ is asserted at the end of a sensors scan, when at least one sensor state has changed 10B EM6420 output pad IRQ is asserted at the end of a sensors scan, when either at least one sensor is active or at least one sensor state has changed 11B EM6420 output pad IRQ is asserted at the end of a sensors scan, when the most activated sensor has changed Table 8-14 : Selection of EM6420 alternate IRQ condition When alternate settings are selected, the alternate Touch Screen IRQ condition defines under which circumstances the EM6420 will assert its IRQ output to signal events happening on the Touch Screen. The IRQ output remains asserted until the new Touch Screen state is returned in response to a getStatus command. The alternate Touch Screen IRQ condition can be modified at any time, even if some other alternate settings are currently being used. However, the new alternate IRQ condition will be taken into account only next time a setAltSettings command is issued. By default, if the setAltIRQCond command has never been sent, the alternate IRQ condition is the same as the base IRQ condition (no change in IRQ generation mode when switching from base to alternate settings). 8.3.12 Command next (SPI protocol only) This is a dummy command that has to be sent while fetching all the bytes of a response, but the last one (see § 8.3.13 and also § 9.2). This command will request the next output byte to be prepared on the EM6420, thus indicating that the transfer isn’t finished. The next command may not be used when the communication bus is idle and no response is expected. If the EM6420 receives a next command in such circumstances, it will assert its IRQ output and return error code 05H. 1 1 1 0 0 0 0 1 C3H 1 7 0 Figure 8-21 : next command format This command can only be used when SPI communication interface is selected, and will cause the EM6420 to assert its IRQ output and return error code 05H if used with any other communication protocol. 8.3.13 Command end This is a dummy command that has to be sent in order to fetch the last desired byte of a response and close the transfer. It indicates the end of a SPI communication frame and lets the EM6420 stop sending data (see § 9.2) 1 1 1 0 0 1 0 1 7 0 CAH 0 Figure 8-22 : end command format It is not necessary to send an end for each intermediate command when several commands are chained. The following command code can be sent directly in place of the end code. That way, the last response byte to the previous command will be retrieved during the transfer of the following command code, and the reception of a new command will automatically close the previous one on the EM6420 side. Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 34 www.emmicroelectronic.com EM6420 The end command may not be used when the communication bus is idle and no response is expected. If the EM6420 receives an end command in such circumstances, it will assert its IRQ output and return error code 05H. Moreover, this command can only be used in SPI mode, and will cause the EM6420 to assert its IRQ output and return error code 05H if used with any other communication protocol. Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 35 www.emmicroelectronic.com EM6420 8.3.14 Command setThreshold This command sets the initial sensor activation threshold. 1 1 1 1 0 0 1 0 7 E5 H 1 0 Threshold 2 7 0 Figure 8-23 : setThreshold command format Threshold values must be in the range from 3 to 200. Invalid values will cause the EM6420 to assert its IRQ output and return error code 04H. The default threshold value is 6 10. The threshold value can only be defined before the Touch Screen interface is started. Attempting to modify that value while the Touch Screen interface is already running will cause the EM6420 to assert its IRQ output and return error code 06H. 8.3.15 Command getAppSettings This command gets the current application settings, i.e. the current Touch Screen scan frequency and the current highest scanned sensor number. 1 1 1 1 0 1 0 0 0 U 2 E8 H 0 7 CSF CHSN 7 ( CSF SHL 4) # CHSN 0 Figure 8-24 : getAppSettings command format Valid values for parameter CHSN range from 0 to 15, thus indicating a number of scanned sensors comprised between 1 and 16. Note that the current sensor number could also be unknown, if it hasn’t been specified by the host processor and the Touch Screen has not been started yet. In that case, the flag U is set, and CHSN contains the highest possible sensor number, depending on the scan frequency, i.e.15 at scan frequencies up to 32 Hz, 7 at 64 Hz and 3 at 128 Hz. Table 8-15 lists valid values for parameter CSF. Note that a 64 Hz or 128 Hz scan frequency can only be obtained with a reduced number of sensors, i.e. 8 at 64 Hz and 4 at 128 Hz. CSF Touch Screen scan frequency CSF Touch Screen scan frequency 000B 1 Hz 100B 16 Hz 001B 2 Hz 101B 32 Hz 010B 4 Hz 110B 64 Hz 011B 8 Hz 111B 128 Hz Table 8-15 : Current Touch Screen scan frequency 8.3.16 Command getVersion This command gets the hardware as well as the software version of the EM6420. 10 Please contact EM Microelectronic-Marin SA to change the default threshold value Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 36 www.emmicroelectronic.com EM6420 1 1 1 1 1 1 0 1 0 7 FAH 0 HV 2 7 0 SMV 3 SRN 7 0 Figure 8-25 : getVersion command format The hardware version is a single 8 bits value. The software version is composed of two nibbles: the SMV nibble is the software major version and the SRN nibble is the software revision number. 8.3.17 Command getStatus This command gets the EM6420 status and deasserts the IRQ output pad, if asserted. If the IRQ was not asserted, the getStatus will return null bytes. NB: For better performance, do not send getStatus requests while no IRQ is asserted. In particular, do not try to read the Touch Screen status by sending this command repeatedly, as it will only slow down the EM6420 and increase its power consumption. 1 1 1 1 1 1 0 0 7 F9 H 0 I 2 1 S Data0 V 7 0 Data 1 3 7 0 Data2 4 7 0 Figure 8-26 : getStatus command format Flag I (Interrupt) is set if the EM6420 IRQ output was asserted when a getStatus command was received. In a multi EM6420 configuration (all IRQ output pads connected to a unique host IRQ input) this flag allows the host to determine which EM6420 device has asserted the IRQ line. When flag I is set, flag S (Special) defines which kind of information is returned to the host processor: When flag S is cleared, a Touch Screen IRQ condition occurred. In this case, parameter Data0 indicates the number of the most activated sensor, parameter Data1 gives the state of sensors 0 to 7 and parameter Data2 gives the state of sensors 8 to 15, as shown in Figure 8-27. Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 37 www.emmicroelectronic.com EM6420 1 1 1 1 1 1 0 0 1 7 1 2 0 V MAS MAS = 1FH if no Touch Screen sensor is active 7 0 S7 S6 S5 S4 S3 S2 S1 S0 3 7 4 F9 H 0 S X is set when corresponding sensor is active 0 S X is cleared when corresponding sensor is not active or does not exist S 15 S 14 S 13 S 12 S 11 S 10 S 9 S 8 7 0 Figure 8-27 : getStatus command format when flag I is set and flag S is cleared When command parameter S is set, the EM6420 returns device status information, mainly error codes, but also the READY status after device startup. In this case, parameter Data0 gives a special code which valid values are listed in Table 8-16. For some special codes, parameters Data1 and Data2 may contain more information as shown in Figure 8-28. For special codes that do not provide complementary information, these parameters are null. 1 1 1 1 1 1 0 0 7 0 1 2 F9 H 1 1 V Code 7 0 Status 0 3 7 0 Status 1 4 7 0 Figure 8-28 : getStatus command format when flags I and S are set The flag V (oVerrun) indicates that the host has missed one or more significant status messages. This happens when the host takes too much time to react to an IRQ, and the EM6420 wants to signal another event while the IRQ line is still active. In this case, the previous important message is deleted, and the host won’t be able to retrieve it anymore. It will only have an indication, through the overflow bit, that at least one message was lost. In case of an overrun, the retrieved message is the most recent message containing the S flag. If none of them contains the S flag, it is the most recent Touch Screen message. Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 38 www.emmicroelectronic.com EM6420 Code Special code description At least one Touch Screen sensor is not correctly connected to the EM6420 device. Command parameters Status0 and Status1 show which sensors seem to be connected. 1 1 1 1 1 1 0 0 1 7 1 2 01H F9 H 0 1 V 0 0 0 0 1 7 0 S7 S6 S5 S4 S3 S2 S1 S0 3 7 S X is cleared when corresponding sensor seems to be defect 0 S X is set when corresponding sensor seems to be connected 4 S 15 S 14 S 13 S 12 S 11 S 10 S 9 S 8 7 0 02H Base settings are invalid. These settings are checked when the Touch Screen interface is started 03H Alternate settings are invalid. These settings are checked once selected as current settings or when the Touch Screen interface is started, if alternate settings are already selected at this moment 04H Bad initial sensor activation threshold 05H Unexpected command received 06H Parameter modification not allowed. Command parameter Status0 returns the command code 07H Reserved for debug purposes Major overflow occurred. Command parameters Status0 and Status1 show which sensor has generated the major overflow. Normally, only one bit is set 1 1 1 1 1 1 0 0 0 1 2 08H F9 H 1 7 1 V 0 1 0 0 0 7 0 S7 S6 S5 S4 S3 S2 S1 S0 3 7 0 S X is cleared when corresponding sensor is working properly S X is set when corresponding sensor has generated a major overflow 4 S 15 S 14 S 13 S 12 S 11 S 10 S 9 S 8 7 0 0FH Unknown command received. Command parameter Status0 returns the command code 10H Reserved for debug purposes 11H Reserved for debug purposes 18H EM6420 is READY to accept communication frames Table 8-16 : EM6420 special codes description 9. EM6420 COMMUNICATION FRAMES All EM6420 commands may be sent by the host using one of the two following communication frames: A Write-Only (WO) communication frame is used to send commands that do not return any values to the host. • • A Write-Read (WR) communication frame is used to send commands that return one or more values to the host. Depending of the selected communication interface, these two communication frames may slightly differ, as explained in details hereafter. Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 39 www.emmicroelectronic.com EM6420 2 9.1 SLAVE I C COMMUNICATION FRAME 2 2 Each I C communication frame must begin with a START condition followed by an I C header and must end with a STOP condition. (Write) WO frame S Slave Address 0 A Command Code A Data 2 I C header A P Additional data by tes (Write) WR frame S Slave Address 0 (Read) A Command Code A Sr Slave Address 2 I C header S Sr P 1 A Data 2 I C header A A P Additional data by tes START c ondition Data s ent from the hos t to the EM6420 Repeated START c ondition Data s ent from the EM6420 to the hos t STOP c ondition Datan A Ac k nowledge (SDA forc ed to V SS) A not Ac k nowledge (SDA not driv en) Figure 9-1: I2C WO and WR communication frames When several commands are sent to the same EM6420 device, the STOP condition is not necessarily be generated between the concatenated communication frames. 9.2 SLAVE SPI COMMUNICATION FRAME As the SPI is a full duplex interface, WO and WR communication frames looks quite the same. However, the host should ignore the values returned by the EM6420 in a WO communication frame. DIx DOx Firs t c ommand c ode rec eiv ed by the EM6420 DIx Dummy v alue returned to the hos t (s hould be ignored) DOx Sec ond c ommand c ode rec eiv ed by the EM6420 Dummy v alue returned to the hos t (s hould be ignored) nSS SDO CK_Pol SDI VDD SCK (1) VSS SCK (0) X X DO7 DI 7 DO6 DO5 DO4 DO3 DO2 DO1 DO0 DI 6 DI5 DI4 DI3 DI 2 DI 1 DI 0 DO7 DI7 X DI7 DO6 DO5 DO4 DO3 DO2 DO1 DO0 DI 6 DI 5 DI4 DI3 DI2 DI 1 DI 0 DI7 X SRDY Figure 9-2: SPI WO communication frames when CK_Pha input is set to VSS Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 40 www.emmicroelectronic.com EM6420 DIx Firs t c ommand c ode rec eiv ed by the EM6420 DOx DIx DOx Dummy v alue returned to the hos t (s hould be ignored) Sec ond c ommand c ode rec eiv ed by the EM6420 Dummy v alue returned to the hos t (s hould be ignored) nSS SDO X SDI CK_Pol X VDD SCK (1) VSS SCK (0) DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0 DO7 DO6 DO5 DO4 DO3 DO2 DO1 DI 7 DI 6 DI5 DI4 DI3 DI 2 DI 1 DI 0 DI 7 DI 6 DI 5 DI4 DI3 DI2 DI 1 DO0 DI0 X SRDY Figure 9-3: SPI WO communication frames when CK_Pha input is set to VDD In a WR communication frame, the EM6420 return the requested values as long as it receives a next command code. Receiving any other command code will terminate the current command and immediately start the new one. DIx Firs t c ommand c ode rec eiv ed by the EM6420 DOx Dummy v alue returned to the hos t (s hould be ignored) Nxx Next c ommand c ode DOx Firs t v alue returned to the hos t in res pons e to the firs t c ommand DIx Sec ond c ommand c ode rec eiv ed by the EM6420 DOx Sec ond v alue returned to the hos t in res pons e to the firs t c ommand DIx Parameter v alue as s oc iated to the s ec ond c ommand DOx Third v alue returned to the hos t in res pons e to the firs t c ommand DOx Fourth v alue returned to the hos t in res pons e to the firs t c ommand DOx Dummy v alue returned to the hos t (s hould be ignored) nSS SDO X SDI CK_Pol X VDD SCK (1) VSS SCK (0) DO7 DI 7 DO6..1 DO0 DI 6..1 DI0 DI7 X DO7 Nx7 DO6..1 DO0 DO7 DO 6..1 DO0 DO7 DO6..1 DO 0 DO7 DO6..1 DO0 Nx6..1 Nx 0 Nx 7 Nx 6..1 Nx7 Nx6..1 Nx 0 DI7 DI6..1 Nx0 DI0 DO7 DI7 X DI7 DO6..1 DO0 DI6..1 DI 0 SRDY Figure 9-4: SPI WR followed by a WO communication frame when CK_Pha input is set to VSS The nSS input of the EM6420 does not need to be deasserted between two communication frames. 9.3 SLAVE 4-BIT PARALLEL COMMUNICATION FRAME The CE input of the EM6420 does not need to be deasserted between two communication frames. DIx Firs t c ommand c ode rec eiv ed by the EM6420 DIx Sec ond c ommand c ode rec eiv ed by the EM6420 DIx Parameter v alue as s oc iated to the firs t c ommand c ode DIx Third c ommand c ode rec eiv ed by the EM6420 CE D 3 ... D0 XH DI7 ...DI 4 DI3 ...DI 0 DI7 ...DI 4 DI3 ...DI 0 DI7 ...DI 4 DI3 ...DI 0 XH DI7 ...DI 4 DI 3...DI 0 CS RD / nWR SRDY Figure 9-5 : Multiple 4-bit parallel WO communication frames Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 41 www.emmicroelectronic.com X EM6420 The falling edge of the RD / nWR input defines the end of a WR communication frame, and therefore the end of the current command. DIx Firs t c ommand c ode rec eiv ed by the EM6420 DOx Firs t data by te returned by the EM6420 DIx Sec ond c ommand c ode rec eiv ed by the EM6420 DOX Sec ond data by te returned by the EM6420 CE D 3 ... D0 XH DI7 ...DI 4 DI3 ...DI 0 XH DO3 ...DO 0 DO7 ...DO 4 DO3 ...DO 0 DO7 ...DO 4 DO3 ...DO 0 DI7 ...DI 4 XH DI3 ...DI 0 CS RD / nWR SRDY Figure 9-6: 4-bit parallel WR followed by a WO communication frame Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 42 www.emmicroelectronic.com EM6420 10. TYPICAL APPLICATIONS Figure 10-1: EM6420 typical application powered by a 3.3 V supply voltage and using the SPI communication interface Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 43 www.emmicroelectronic.com EM6420 Figure 10-2: EM6420 typical application powered by a 1.2 V supply voltage and using the I2C communication interface Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 44 www.emmicroelectronic.com EM6420 Figure 10-3: EM6420 typical standalone application powered by a 3.3 V supply voltage For better ESD protection in customer application, it is strongly recommended to connect the bulk of the EM6420 to VSS. Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 45 www.emmicroelectronic.com EM6420 11. PAD LOCATION DIAGRAM 31 32 30 29 26 27 28 25 24 23 22 21 20 19 33 18 34 17 35 EM6420 16 36 15 37 38 14 39 13 40 Y 41 12 2 1 3 4 5 6 7 8 9 10 11 0,0 X Figure 11-1 : EM6420 pad location diagram Chip dimensions Die size : Die thickness : X = 2'130 µm ± 100 µm Y = 2'224 µm ± 100 µm 279.4 µm ± 25.4 μm (83.86 mils ± 3.94 mils) (87.56 mils ± 3.94 mils) (10 mils ± 1 mils) Table 11-1: EM6420 chip dimensions Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 46 www.emmicroelectronic.com EM6420 Pad Number Pad Name X [µm] 1 VSS 312.000 2 CBL 3 Y [µm] Pad Number Pad Name X [µm] Y [µm] 143.625 22 TIC 1'818.000 2'080.375 432.000 143.625 23 TCK 1'698.000 2'080.375 CBH 552.000 143.625 24 LSV 1'578.000 2'080.375 4 VCP 672.000 143.625 25 IRQ 1'458.000 2'080.375 5 VDDA 792.000 143.625 26 CI8 1'290.000 2'080.375 6 S15 912.000 143.625 27 CIO7 1'170.000 2'080.375 7 S11 1'132.000 143.625 28 CIO6 1'050.000 2'080.375 8 S14 1'252.000 143.625 29 CIO5 930.000 2'080.375 9 S10 1'472.000 143.625 30 CIO4 810.000 2'080.375 10 S7 1'592.000 143.625 31 En 690.000 2'080.375 11 S6 1'812.000 143.625 32 VDD 500.000 2'080.375 12 S5 1'986.375 312.000 33 CIO3 143.625 1'368.000 13 S4 1'986.375 532.000 34 CIO2 143.625 1'248.000 14 S9 1'986.375 652.000 35 CIO1 143.625 1'128.000 15 S13 1'986.375 872.000 36 CIO0 143.625 960.000 16 S3 1'986.375 992.000 37 CIS2 143.625 792.000 17 S12 1'986.375 1'212.000 38 CIS1 143.625 672.000 18 S2 1'986.375 1'332.000 39 CIS0 143.625 552.000 19 S8 1'986.375 1'552.000 40 VDDD 143.625 432.000 20 S1 1'986.375 1'672.000 41 VDD 143.625 312.000 21 S0 1'986.375 1'892.000 X, Y coordinates refers to the center of the pads. The origin (0, 0) is the bottom left corner of the circuit scribe line. Table 11-2 : EM6420 pads coordinates Standard die version Gold bump version Pads opening 72 µm x 72 µm Bump size : 68 µm x 68 µm ± 5 µm Minimum pad pitch : 120 µm Bump height : 17.5 µm ± 3 µm Bump height co-planarity < 2 µm within die < 4 µm within wafer Bump roughness < 2 µm Bump hardness : 30 – 90 HV (soft bump) Minimum bump space 52 µm edge to edge Shear force : > 7.2 mg / µm2 PI thickness No PI layer Table 11-3 : EM6420 pads and gold bumps additional information Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 47 www.emmicroelectronic.com EM6420 12. PACKAGE INFORMATION En CIO 4 CIO 5 CIO 6 CIO 7 CI8 IRQ LSV TCK TIC 40 39 38 37 36 35 34 33 32 31 12.1 SAWN 40-PIN MICRO LEAD FRAME 2 – 6 X 6 MM BODY S12 CIS 1 6 25 S3 CIS 0 7 24 S13 VDDD 8 23 S9 VDD 9 22 S4 VSS 10 21 S5 The exposed pad of the package is connected to the bulk of the device S6 20 26 19 5 S7 CIS 2 18 S2 S10 27 17 4 S14 CIO 0 16 S8 S11 28 15 3 S15 CIO 1 14 S1 VDDA 29 13 2 VCP CIO 2 12 S0 CBH 30 11 1 CBL CIO 3 Figure 12-1 : 40-pin Micro Lead Frame 2 Pin Assignment (TOP view) Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 48 www.emmicroelectronic.com EM6420 The exposed pad of the package is connected to the bulk of the device D2 D PIN #1 ID PIN #1 ID N N-1 N-1 N SEE DETAIL «A» NXL 1 1 2 2 3 3 E E2 (Ne - 1) X e k e NXb (Nd - 1) X e SEE DETAIL «A» TOP VIEW BOTTOM VIEW L1 L A e SEATING PLANE e/2 A1 A3 SIDE VIEW Symbol A A1 A3 D D2 E E2 Min 0.80 0.00 4.00 4.00 Dimensions Nom 0.85 0.02 0.20 REF 6.00 BSC 4.10 6.00 BSC 4.10 DETAIL «A» Max 0.90 0.05 Symbol 11 N 12 Nd 13 Ne e 4.20 L L1 4.20 b All dimensions are in mm 11 N is the number of terminals 12 Nd is the number of terminals in X-direction 13 Ne is the number of terminals in Y-direction Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 Min 49 0.35 0.00 0.18 Dimensions Nom 40 10 10 0.50 BSC 0.40 0.25 Max 0.45 0.15 0.30 www.emmicroelectronic.com EM6420 En CIO 4 CIO 5 CIO 6 CIO 7 CI8 IRQ LSV TCK 36 35 34 33 32 31 30 29 28 12.2 SAWN 36-PIN MICRO LEAD FRAME 2 – 5 X 5 MM BODY 23 S2 CIS 1 6 22 S3 CIS 0 7 21 S9 VDDD 8 20 S4 VDD 9 19 S5 18 5 S6 CIS 2 17 S8 S7 24 16 4 S10 CIO 0 15 S1 S11 25 14 3 VDDA CIO 1 13 S0 VCP 26 12 2 CBH CIO 2 11 TIC CBL 27 10 1 VSS CIO 3 The exposed pad of the package is connected to the bulk of the device Figure 12-2 : 36-pin Micro Lead Frame 2 Pin Assignment (Top View) Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 50 www.emmicroelectronic.com EM6420 The exposed pad of the package is connected to the bulk of the device D2 D N PIN #1 ID N -1 N-1 SEE D ETAIL « A» PIN #1 ID N N xL 1 1 2 2 3 3 E E2 (N e -1 ) x e N xb e SEE D ETAIL « A» (N d -1 ) x e TOP VIEW BOTTOM VIEW L1 L A e A1 A3 SIDE VIEW DETAIL «A» Dimensions Dimensions Symbol Symbol Min A A1 0.80 0.00 Nom 0.85 0.02 Max Min 0.90 N 0.05 14 Nd A3 0.20 REF Ne D 5.00 BSC e D2 3.50 E E2 3.60 3.70 5.00 BSC 3.50 3.60 3.70 Nom Max 36 15 9 16 9 0.40 BSC L 0.35 L1 0.00 b 0.15 0.40 0.45 0.15 0.20 0.25 All dimensions are in mm 14 N is the number of terminals 15 Nd is the number of terminals in X-direction 16 Ne is the number of terminals in Y-direction Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 51 www.emmicroelectronic.com EM6420 CIO 5 CIO 6 CIO 7 CI8 IRQ LSV TCK TIC 32 31 30 29 28 27 26 25 12.3 SAWN 32-PIN MICRO LEAD FRAME 2 – 5 X 5 MM BODY CIO 1 5 20 S4 CIO 0 6 19 S5 CIS 2 7 18 S6 CIS 1 8 17 S7 16 S3 VDDA 21 15 4 VCP CIO 2 14 S2 CBH 22 13 3 CBL CIO 3 12 S1 VSS 23 11 2 VDD En 10 S0 VDDD 24 9 1 CIS0 CIO 4 The exposed pad of the package is connected to the bulk of the device Figure 12-3 : 32-pin Micro Lead Frame 2 Pin Assignment (Top View) Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 52 www.emmicroelectronic.com EM6420 The exposed pad of the package is connected to the bulk of the device D2 D N PIN #1 ID N -1 N-1 SEE D ETAIL « A» PIN #1 ID N N xL 1 1 2 2 3 3 E E2 (N e -1 ) x e N xb e SEE D ETAIL « A» (N d -1 ) x e TOP VIEW BOTTOM VIEW L1 L A e A1 e/2 A3 SIDE VIEW DETAIL «A» Dimensions Dimensions Symbol Symbol Min A A1 0.80 0.00 Nom 0.85 0.02 Max Min 0.90 N 0.05 17 Nd A3 0.20 REF Ne D 5.00 BSC e D2 3.50 E E2 3.60 3.70 5.00 BSC 3.50 3.60 3.70 Nom Max 32 18 8 19 8 0.50 BSC L 0.35 L1 0.00 b 0.18 0.40 0.45 0.15 0.25 0.30 All dimensions are in mm 17 N is the number of terminals 18 Nd is the number of terminals in X-direction 19 Ne is the number of terminals in Y-direction Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 53 www.emmicroelectronic.com EM6420 13. ORDERING INFORMATION Part number Delivery Form EM6420V3WS10 Sawn wafer, 10 mils thickness EM6420V3WS10E Sawn wafer with gold bumps, 10 mils thickness EM6420V3LF40D+ 40-pin sawn Micro Lead Frame 2 (40-pin MLF2), Tray EM6420V3XXXX+ For other options please contact the EM Microelectronic-Marin SA sales representative. EM6420V4WS10 Sawn wafer, 10 mils thickness Part number Hardware version Software version I C Multi Chip mode Minimum scan frequency 3 1-6 Supported 1 Hz 3 2-0 Supported 1 Hz 2 EM6420V3WS10 EM6420V3WS10E EM6420V3LF40D+ EM6420V3XXXX+ EM6420V4WS10 EM Microelectronic-Marin SA (EM) makes no warranty for the use of its products, other than those expressly contained in the Company's standard warranty which is detailed in EM's General Terms of Sale located on the Company's web site. EM assumes no responsibility for any errors which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without notice, and does not make any commitment to update the information contained herein. No licenses to patents or other intellectual property of EM are granted in connection with the sale of EM products, expressly or by implications. EM's products are not authorized for use as components in life support devices or systems. Copyright 2012, EM Microelectronic-Marin SA 6420-DS.doc, Version 4.0 , 4-Jun-12 54 www.emmicroelectronic.com