MMA81XXTKEG Rev 0, 12/2009 Freescale Semiconductor Technical Data Digital X-Axis or Z-Axis Accelerometer The MMA81XXTKEG (Z-axis) and MMA82XXTKEG (X-axis) are members of Freescale’s family of DSI 2.0-compatible accelerometers. These devices incorporate digital signal processing for filtering, trim and data formatting. MMA81XXTKEG MMA82XXTKEG SERIES Features • Available in 20g, 40g, 50g, 100g, 150g, and 250g (MMA82XXTKEG, X-axis) and 40g, 100g, 150g, and 250g (MMA81XXTKEG, Z-axis). Additional g-ranges may be available upon request • 80 customer-accessible OTP bits • 10-bit digital data output from 8 to 10 bit DSI output • 6.3 to 30 V supply voltage • On-chip voltage regulator • Internal self-test • Minimal external component requirements • RoHS compliant (-40 to +125ºC) 16-pin SOIC package • DSI 2.0 Compliant • Z-axis transducer is overdamped • Qualified AEC-Q100, Rev. F Grade 2 (-40°C/ +105°C) SINGLE-AXIS DSI 2.0 ACCELEROMETER TKEG SUFFIX (Pb-free) 16-LEAD SOIC CASE 475-01 PIN CONNECTIONS Typical Applications • Crash detection (Airbag) • Impact and vibration monitoring • Shock detection. N/C 1 16 N/C 2 15 VSS CREG 3 14 BUSRTN VPP/TEST 4 13 BUSIN CFIL 5 12 BUSOUT DOUT 6 11 HCAP VGND/DIN 7 10 CLK 8 9 16-PIN SOIC PACKAGE © Freescale Semiconductor, Inc., 2009. All rights reserved. VSS VSS CREG ORDERING INFORMATION Device Name X-axis g-Level Z-axis g-Level Temperature Range SOIC 16 Package Packaging MMA8225EGR2 250 — -40 to +125°C 475-01 Tape & Reel MMA8225EG 250 — -40 to +125°C 475-01 Tubes MMA8225TKEGR2* 250 — -40 to +125°C 475-01 Tape & Reel MMA8225TKEG* 250 — -40 to +125°C 475-01 Tubes MMA8215EGR2 150 — -40 to +125°C 475-01 Tape & Reel MMA8215EG 150 — -40 to +125°C 475-01 Tubes MMA8210TEGR2 100 — -40 to +125°C 475-01 Tape & Reel MMA8210TEG 100 — -40 to +125°C 475-01 Tubes MMA8210TKEGR2* 100 — -40 to +125°C 475-01 Tape & Reel MMA8210TKEG* 100 — -40 to +125°C 475-01 Tubes MMA8205TEGR2 50 — -40 to +125°C 475-01 Tape & Reel MMA8205TEG 50 — -40 to +125°C 475-01 Tubes MMA8205TKEGR2* 50 — -40 to +125°C 475-01 Tape & Reel MMA8205TKEG* 50 — -40 to +125°C 475-01 Tubes MMA8204EGR2 40 — -40 to +125°C 475-01 Tape & Reel MMA8204EG 40 — -40 to +125°C 475-01 Tubes MMA8204TKEGR2* 40 — -40 to +125°C 475-01 Tape & Reel MMA8204TKEG* 40 — -40 to +125°C 475-01 Tubes MMA8202EGR2 20 — -40 to +125°C 475-01 Tape & Reel MMA8202EG 20 — -40 to +125°C 475-01 Tubes MMA8125EGR2 — 250 -40 to +125°C 475-01 Tape & Reel MMA8125EG — 250 -40 to +125°C 475-01 Tubes MMA8125TKEGR2* — 250 -40 to +125°C 475-01 Tape & Reel MMA8125TKEG* — 250 -40 to +125°C 475-01 Tubes MMA8115EGR2 — 150 -40 to +125°C 475-01 Tape & Reel MMA8115EG — 150 -40 to +125°C 475-01 Tubes MMA8110EGR2 — 100 -40 to +125°C 475-01 Tape & Reel MMA8110EG — 100 -40 to +125°C 475-01 Tubes MMA8110TKEGR2* — 100 -40 to +125°C 475-01 Tape & Reel MMA8110TKEG* — 100 -40 to +125°C 475-01 Tubes MMA8104EGR2 — 40 -40 to +125°C 475-01 Tape & Reel MMA8104EG — 40 -40 to +125°C 475-01 Tubes MMA8104TKEGR2* — 40 -40 to +125°C 475-01 Tape & Reel MMA8104TKEG* — 40 -40 to +125°C 475-01 Tubes *Part number sourced from a different facility. MMA81XXTKEG 2 Sensors Freescale Semiconductor SECTION 1 GENERAL DESCRIPTION MMA81XXTKEG/MMA82XXTKEG family is a satellite accelerometer which is comprised of a single axis, variable capacitance sensing element with a single channel interface IC. The interface IC converts the analog signal to a digital format which is transmitted in accordance with the DSI-2.0 specification. 1.1 OVERVIEW Signal conditioning begins with a Capacitance to Voltage conversion (C to V) followed by a 2-stage switched capacitor amplifier. This amplifier has adjustable offset and gain trimming and is followed by a low-pass switched capacitor filter with Bessel function. Offset and gain of the interface IC are trimmed during the manufacturing process. Following the filter the signal passes to the output stage. The output stage sensitivity incorporates temperature compensation. The output of the accelerometer signal conditioning is converted to a digital signal by an A/D converter. After this conversion the resultant digital word is converted to a serial data stream which may be transmitted via the DSI bus. Power for the device is derived from voltage applied to the BUSIN/BUSOUT and VSS pins. Bus voltage is rectified and applied to an external capacitor connected to the HCAP pin. During data transmissions, the device operates from stored charge on the external capacitor. An integrated regulator supplies fixed voltage to internal circuitry. A self-test voltage may be applied to the electrostatic deflection plate in the sensing element. Self-Test voltage is factory trimmed. Other support circuits include a bandgap voltage reference for the bias sources and the self-test voltage. A total of 128 bits of One-Time Programmable (OTP) memory, are provided for storage of factory trim data, serial number and device characteristics. Eighty OTP bits are available for customer programming. These eighty OTP bits may be programmed via the DSI Bus or through the serial test/trim interface. OTP integrity is verified through continuous parity checking. Separate parity bits are provided for factory and customer programmed data. In the event that a parity fault is detected, the reserved value of zero is transmitted in response to a Read Acceleration Data command. A block diagram illustrating the major elements of the device is shown in Figure 1-1. MMA81XXTKEG Sensors Freescale Semiconductor 3 REGULATOR TRIM HCAP BUSIN 11 VSS BUSRTN 12 CREG BUSOUT 2 16 15 10 14 GROUND LOSS DETECTOR BANDGAP REFERENCE LOGIC COMMAND DECODE STATE MACHINE RESPONSE GENERATION OSCILLATOR SELFTEST TRIM OSC TRIM SELFTEST VOLTAGE 7 4 OTP PROGRAMMING INTERFACE 6 8 SELF-TEST ENABLE A-TO-D CONVERTER g-CELL 3 CREG 1 N/C VSS INTERNAL SUPPLY VOLTAGE 13 N/C VSS 9 VOLTAGE REGULATOR C-TO-V CONVERTER GAIN TRIM OFFSET TRIM VPP/TEST DOUT CLK SWITCHES SHOWN IN NORMAL OPERATING CONFIGURATION 5 LOW-PASS FILTER VGND/DIN CFIL TCS TRIM Figure 1-1. Overall Block Diagram MMA81XXTKEG 4 Sensors Freescale Semiconductor 1.2 PACKAGE PINOUT The pinout for this 16-pin device is shown in Figure 1-2. +Z +X N/C 1 16 VSS N/C 2 15 VSS CREG 3 14 BUSRTN VPP/TEST 4 13 BUSIN CFIL 5 12 BUSOUT DOUT 6 11 HCAP VGND/DIN 7 10 VSS CLK 8 9 -Z -X CREG 16-PIN SOIC PACKAGE ACTIVATION OF Z-AXIS SELF-TEST CAUSES OUTPUT TO BECOME MORE POSITIVE PROJECTION ACTIVIATION OF X-AXIS SELF-TEST CAUSES OUTPUT TO BECOME MORE POSITIVE CASE: 475-01 N/C: NO INTERNAL CONNECTION Output response to displacement in the direction of arrows. +1 g +1 g 0g 0g -1 g 0g 0g TO CENTER OF GRAVITATIONAL FIELD -1 g Response to static orientation within 1 g field. Figure 1-2. Device Pinout MMA81XXTKEG Sensors Freescale Semiconductor 5 1.3 PIN FUNCTIONS The following paragraphs provide descriptions of the general function of each pin. 1.3.1 HCAP and VSS Power is supplied to the ASIC through BUSIN or BUSOUT and BUSRTN. The supply voltage is rectified internally and applied to the HCAP pin. An external capacitor connected to HCAP forms the positive supply for the integrated voltage regulator. VSS is supply return node. All VSS pins are internally connected to BUSRTN. To obtain specified performance, all VSS nodes should be connected to the BUSRTN node on the PWB. To ensure stability of the internal voltage regulator and meet DFMEA requirements, the connection from HCAP to the external capacitor should be as short as possible and should not be routed elsewhere on the printed wiring assembly. The voltage on HCAP is monitored. If the voltage falls below a specified level, the device will return the value zero in response to a short word Read Acceleration Data command, and report the undervoltage condition by setting the Undervoltage (U) flag. Should the undervoltage condition persist for more than one millisecond, the internal Power-On Reset (POR) circuit is activated and the device will not respond until the voltage at HCAP is restored to operating levels and the device has undergone post-reset initialization. 1.3.2 BUSIN The BUSIN pin is normally connected to the DSI bus and supports bidirectional communication with the master. MMA81XXEG supports reverse initialization for improved system fault tolerance. In the event that the DSI bus cannot support communication between the master and BUSIN pin, communication with the master may be conducted via the BUSOUT pin and the BUSIN pin can be used to access other DSI devices. 1.3.3 BUSOUT The BUSOUT pin is normally connected to the DSI bus for daisy-chained bus configurations. In support of fault tolerance at the system level, the BUSOUT pin can be used as an input for reverse initialization and data communication. The internal bus switch is always open following reset. The bus switch is closed when data bit D6 is set when an Initialization or Reverse Initialization command is received. 1.3.4 BUSRTN This pin provides the common return for power and signalling. 1.3.5 CREG The internal voltage regulator requires external capacitance to the VSS pin for stability. This should be a high grade capacitor without excessive internal resistance or inductance. An optional electrolytic capacitor may be required if a longer power down delay is required. Figure 1-3 illustrates the relationship between capacitance, series resistance and voltage regulator stability. Two CREG pins are provided for redundancy. It is recommended that both CREG pins are connected to the external capacitor(s) for best system reliability. STABLE, UNACCEPTABLE NOISE PERFORMANCE UNSTABLE 700 mΩ ESR STABLE 0 1 μF 100 μF CREG Figure 1-3. Voltage Regulator Capacitance and Series Resistance MMA81XXTKEG 6 Sensors Freescale Semiconductor 1.3.6 CFIL The output of the sensor interface circuitry can be monitored at the CFIL pin. An internal buffer is provided to provide isolation between external signals and the input to the A/D converter. If CFIL monitoring is desired, a low-pass filter and a buffer with high input impedance located as close to this pin as possible are required. The circuit configuration shown in Figure 1-5 is recommended. MMA81XXTKEG/MMA82XXTKEG RIN ≥ 1 MΩ 50 kΩ CFIL 5 680 pF Figure 1-4. CFIL Filter and Buffer Configuration This pin may be configured as an input to the A/D converter when the MMA81XXTKEG/MMA82XXTKEG device is in test mode. Refer to Appendix A for further details regarding test mode operation. 1.3.7 Trim/Test Pins (VPP/TEST, CLK, DOUT) These pins are used for programming the device during manufacturing. These pins have internal pull-up or pull-down devices to drive the input when left unconnected. The following termination is recommended for these pins in the end application: Table 1-1 PIN Termination VPP/TEST Connect to ground CLK Leave unconnected DOUT Leave unconnected CLK may be connected to ground, however this is not advised if the GLDE bit in DEVCFG2 is set, as a short between the adjacent VGND/DIN pin and ground prevents ground loss detection. 1.3.8 GND Detect Pin (VGND/DIN) VGND/DIN may be used to detect an open condition between the satellite module and chassis. The ground loss detector circuit supplies a constant current through VGND/DIN and measures resulting voltage. This determines the resistance between VGND/ DIN and the system’s virtual ground. A fault condition is signalled if the resistance exceeds specified limits. This pin has no internal pull-down device and must be connected as shown in Figure 1-5. Ground loss detection circuitry is enabled when the GLDE bit is programmed to a logic ‘1’ state in DEVCFG2. Ground loss detection is not available when the master operates in differential mode. VGND/DIN must be directly connected to BUSRTN if the DSI bus is configured for differential operation. VGND/DIN connection options are illustrated in Figure 1-5. When ground loss detection is enabled, a constant current is sourced and the voltage at VGND is continuously monitored. An open connection between VSS and chassis ground will cause the voltage to rise. If the voltage indicates that the connection between chassis ground and VSS has opened, a 14-bit counter is enabled. This counter will reverse if the voltage falls below the detection threshold. Should the counter overflow, a ground loss condition is indicated. The counter acts as a digital low-pass filter, to provide immunity from spurious signals. This pin functions as the SPI data input when the device is in test mode. MMA81XXTKEG Sensors Freescale Semiconductor 7 GROUND-LOSS DETECTION DISABLED MMA81XXTKEG/MMA82XXTKEG 1 2 3 4 5 6 7 8 N/C VSS N/C VSS CREG BUSRTN VPP/TEST CFIL BUSIN BUSOUT DOUT VGND/DIN CLK HCAP VSS CREG GROUND-LOSS DETECTION ENABLED (SINGLE-ENDED SYSTEMS ONLY) MMA81XXTKEG/MMA82XXTKEG 16 1 15 2 14 3 13 4 12 5 11 6 10 BUSRTN 7 8 9 N/C VSS N/C VSS CREG BUSRTN VPP/TEST CFIL BUSIN BUSOUT DOUT HCAP VGND/DIN CLK VSS CREG 16 15 14 BUSRTN 13 12 11 10 9 1.00 kΩ, 1% CHASSIS 1 nF Figure 1-5. VGND/DIN Connection Options 1.4 MODULE INTERCONNECT A typical satellite module configuration supporting daisy-chain configuration is shown in Figure 1-6. Capacitors C1 and C2 form a filter network for the internal voltage regulator. Two capacitors are shown for redundancy; this configuration improves reliability in the event of an open capacitor connection. A single 1 μF capacitor may be used in place of C1 and C2, however connection from the capacitor to both CREG pins is required. CHOLD stores energy during signal transitions on BUSIN and BUSOUT. The value of this capacitor is typically 1 μF; however, this depends upon data rates and bus utilization. MMA81XXTKEG/MMA82XXTKEG 1 2 3 4 5 SEE NOTE N/C 6 7 8 N/C VSS N/C VSS CREG VPP/TEST CFIL DOUT VGND/DIN CLK C1 1 μF BUSRTN BUSIN BUSOUT HCAP VSS CREG 16 15 14 13 BUSIN 12 BUSOUT 11 10 9 C2 1 μF CHOLD BUSRTN NOTE: LEAVE OPEN OR CONNECT TO SIGNAL MONITOR. Figure 1-6. Typical Satellite Module Diagram 1.5 DEVICE IDENTIFICATION Thirty-two OTP bits are factory-programmed with a unique serial number during the manufacturing and test. Five additional bits are factory-programmed to indicate the full-scale range and axis of sensitivity. Device identification data may be read at any time while the device is active. MMA81XXTKEG 8 Sensors Freescale Semiconductor SECTION 2 SUPPORT MODULES 2.1 MASTER OSCILLATOR A temperature-compensated internal oscillator provides a stable timing reference for the device. The oscillator is factory-trimmed to operate at a nominal frequency of 4 MHz. 2.2 VOLTAGE REGULATION The internal voltage regulator has minimum voltage level detection, which will hold the device in reset and prevent data transmission should the regulator output fall during operation. The regulator also has an input voltage clamp to limit the power dissipated in the regulator during voltage spikes on the HCAP pin which might come from the two or three wire satellite bus. 2.3 BESSEL FILTER 180-Hz, 2-pole and 400 Hz 4-pole Bessel filter options are provided. The low-pass filter is implemented within a two stage switched capacitor amplifier. The overall gain of the Bessel filter is set to a fixed value. The output of the Bessel filter output acts as the input to the A/D converter and is also buffered and made available at the CFIL pin. 2.4 STATUS MONITORING A number of abnormal conditions are detected by MMA81XXTKEG/MMA82XXTKEG and the behavior of the device altered if a fault is detected. Detected fault conditions and consequent device behavior is summarized in the table below. Certain conditions, e.g. ground loss, are qualified by device configuration. Figure 2-1 provides a representation of fault conditions, applicable qualifiers and effects. Table 2-1 Fault Condition Response Summary Condition Undervoltage, CREG Sustained Undervoltage, HCAP Frame Timeout Transient Undervoltage, HCAP Description Internally regulated voltage below operating level Device Behavior Device continuously undergoes reset, bus switch open, no response to DSI commands Voltage at HCAP below operating level for more than 1 ms Bus voltage remains below frame threshold (tTO) longer than specified time. Voltage at HCAP below operating level for less than 1 ms Undervoltage (U) flag set, short-word Read Acceleration Data response value equals zero Fuse Fault OTP fuse threshold failure Parity Fault Parity failure detected in factory or customer programmed OTP data Accelerometer Status (S) flag set, short-word Read Acceleration Data response value equals zero Ground Fault Ground loss detected for more than 4.096 ms Accelerometer Status (S) and Ground Fault (GF) flags set, short-word Read Acceleration Data response value equals zero MMA81XXTKEG Sensors Freescale Semiconductor 9 ST STDIS S 1 D SHORT WORD ACCELERATION DATA = 0 Q DDIS R FUSE ERROR TRANSIENT UNDERVOLTAGE CONDITION GF GLDE U LOCK1 PAR1 FAULT LOCK2 PAR2 FAULT KEY: DDIS DEVICE DISABLE BIT, DEVCFG2[4] FUSE FAULT OTP FUSE THRESHOLD FAILURE GLDE GROUND LOSS DETECTION BIT, DEVCFG2[5] GF GROUND FAULT DETECTION CONDITION LOCK1 FACTORY PROGRAMMED OTP LOCK BIT LOCK2 CUSTOMER PROGRAMMED OTP LOCK BIT PAR1 FAULT FACTORY PROGRAMMED OTP PARITY FAULT CONDITION PAR2 FAULT CUSTOMER PROGRAMMED OTP PARITY FAULT CONDITION S ACCELEROMETER STATUS FLAG ST SELF-TEST ACTIVATION CONDITION STDIS SELF-TEST DISABLE U UNDERVOLTAGE FLAG Figure 2-1. Status Logic Representation The signal STDIS in Figure 2-1 is set when self-test lockout is activated through the execution of two consecutive Disable SelfTest Stimulus commands, as described in Section 4.6.6. If self-test lockout has been activated, a DSI Clear command or poweron reset is required to clear a fault condition which results in reset of the D flip-flop. MMA81XXTKEG 10 Sensors Freescale Semiconductor SECTION 3 OTP MEMORY MMA81XXTKEG/MMA82XXTKEG family features One-Time-Programmable (OTP) memory implemented via a fuse array. OTP is organized as an array of 96 bits which contains the trim data, configuration data, and serial number for each device. Sixteen bits of the OTP array may be programmed by the customer through the DSI Bus. 3.1 INTERNAL REGISTER ARRAY AND OTP MEMORY Contents of OTP memory are transferred to a set of registers following power-on reset, after which the OTP array is powereddown. Contents of the register array are static and may be read at any time following the transfer of data from the OTP memory. Write operations to OTP mirror registers are supported when the device is in test mode, however any data stored in the register will be lost when the device is powered down. The mirror registers are also restored when an OTP read operation is performed. In addition to the registers which mirror OTP memory contents, several other registers are provided. Among these are the OTP Control Registers which controls OTP programming operations and may be used to restore the registers from the OTP memory. CLK SERIAL PERIPHERAL INTERFACE DOUT TO DIGITAL INTERFACE REGISTER ARRAY DIN OTP ARRAY VPP/TEST Figure 3-1. OTP Interface Overview 3.2 OTP WORD ASSIGNMENT Customer-accessible OTP bits are shown in Table 3-1. Unprogrammed OTP bits are read as logic ‘0’ values. DEVCFG1, DEVCFG2 and registers REG-8 through REG-F are programmed by the customer. Other bits are programmed and locked during manufacturing. There is no requirement to program any bits in DEVCFG1 or DEVCFG2 for the device to be fully operational. Table 3-1 Customer Accessible Data Location Address Bit Function Register 7 6 5 4 3 2 1 0 $00 SN0 S7 S6 S5 S4 S3 S2 S1 S0 $01 SN1 S15 S14 S13 S12 S11 S10 S9 S8 $02 SN2 S23 S22 S21 S20 S19 S18 S17 S16 $03 SN3 S31 S30 S29 S28 S27 S26 S25 S24 $04 TYPE ORDER 0 AXIS 0 0 RNG2 RNG1 RNG0 $05 RESERVED 0 0 0 0 0 0 0 0 $06 DEVCFG1 AT1 AT0 $07 DEVCFG2 AD1 AD0 Customer Defined LOCK2 PAR2 GLDE DDIS AD3 AD2 MMA81XXTKEG Sensors Freescale Semiconductor 11 Table 3-1 Customer Accessible Data Location Bit Function Address Register $08 REG-8 Customer Defined $09 REG-9 Customer Defined $0A REG-A Customer Defined $0B REG-B Customer Defined $0C REG-C Customer Defined $0D REG-D Customer Defined $0E REG-E Customer Defined $0F REG-F Customer Defined 3.2.1 7 6 5 4 3 2 1 0 Device Serial Number A unique serial number is programmed into each device during manufacturing. The serial number is composed of the following information. Table 3-2 Serial Number Assignment Bit Range Content S12 - S0 Serial Number S31 - S13 Lot Number Lot numbers begin at 1 for all devices produced and are sequentially assigned. Serial numbers begin at 1 for each lot, and are sequentially assigned. No lot will contain more devices than can be uniquely identified by the 13-bit serial number. Not all allowable lot numbers and serial numbers will be assigned. 3.2.2 Type Byte The Type Byte is programmed at final trim and test to indicate the axis of orientation of the g-cell and the calibrated range of the device. Table 3-3 Device Type Register Location Bit Function Address Register 7 6 5 4 3 2 1 0 $04 TYPE ORDER 0 AXIS 0 0 RNG2 RNG1 RNG0 3.2.2.1 Filter Characteristic Bit (ORDER) This bit denotes the low-pass filter characteristic. 0 - 400 Hz, 4-pole 1 - 180 Hz, 2-pole 3.2.2.2 Bit 6 Bit 6 is reserved. It will always be read as a logic ‘0’ value. 3.2.2.3 Axis of Sensitivity Bit (AXIS) The AXIS bit indicates direction of sensitivity 0 - Z-axis 1 - X-axis 3.2.2.4 Bit 4, Bit 3 Bit 4 and Bit 3 are reserved. They will always be read as a logic ‘0’ value. MMA81XXTKEG 12 Sensors Freescale Semiconductor 3.2.2.5 Full-Scale Range Bits (RNG2 - RNG0) These three bits define the calibrated range of the device as follows: Table 3-4 3.2.3 RNG2 RNG1 RNG0 Range 0 0 0 Unused 0 0 1 20g 0 1 0 40g 0 1 1 50g 1 0 0 100g 1 0 1 150g 1 1 0 250g 1 1 1 Unused Configuration Bytes Two customer-programmable configuration bytes are assigned. 3.2.4 Device Configuration Byte 1 (DEVCFG1) Table 3-5 Device Configuration Byte 1 Location Address Register $06 DEVCFG1 Bit Function 7 6 5 4 3 2 Customer Defined 1 0 ATT1 ATT0 Configuration Byte 1 contains three defined bit functions, plus five bits that can be programmed by the customer to designate any coding desired for packaging axis, model, etc. 3.2.5 Attribute Bits (AT1, AT0) These bits may be assigned by the customer as desired. They are transmitted by MMA81XXTKEG/MMA82XXTKEG in response to Request Status, Disable Self-Test Stimulus or Enable Self-Test Stimulus commands, as described in Section 4. 3.2.6 Device Configuration Byte 2 (DEVCFG2) Table 3-6 Device Configuration Byte 2 Location Bit Function Address Register 7 6 5 4 3 2 1 0 $07 DEVCFG2 LOCK2 PAR2 GLDE DDIS AD3 AD2 AD1 AD0 Configuration Byte 2 contains six bits that can be programmed by the customer to control device configuration, along with parity and lock bits for DEVCFG1 and DEVCFG2. 3.2.6.1 Customer Data Lock Bit (LOCK2) The bits in configuration bytes 1 and 2 are frozen when the LOCK2 bit is programmed. The LOCK2 bit is not included in the parity check. Locking does not take effect after this bit is programmed until the device has been subsequently reset. 0 - Customer-programmed data area unlocked. 1 - Programming operations inhibited. The DDIS bit is not affected by LOCK2 and may be programmed at any time. 3.2.6.2 Customer Data Parity Bit (PAR2) The PAR2 parity bit is used for detecting changes in configuration bytes 1 and 2 along with registers REG-8 through REG-F (addresses $06 through $0F, inclusive). A fault condition is indicated if a change to parity-protected register data is detected. The PAR2 bit follows an “even” parity scheme (number of logical HIGH bits including parity bit is even). MMA81XXTKEG Sensors Freescale Semiconductor 13 If an internal parity error is detected, the device will respond to Read Acceleration Data commands with zero in the data field, as described in Section 4.5.4. The Status (S) bit will be set in either short word or long word responses to indicate the fault condition. A parity fault may result from a bit failure within the OTP or the registers which store an image of the OTP during operation. In the latter case, power-on reset will clear the fault when the registers are re-loaded. A parity fault associated with the OTP array is a non-recoverable failure. The parity status of customer programmed data is not monitored if the LOCK2 bit is not programmed to a logic ‘1’ state. 3.2.6.3 Ground Loss Detection Enable (GLDE) When this bit is programmed to a logic ‘1’ value, ground loss errors will be reported if a ground fault condition is detected. 1 - Ground-loss detection circuitry enabled 0 - Ground-loss detection disabled. MMA81XXTKEG 14 Sensors Freescale Semiconductor 3.2.6.4 Device Disable Bit (DDIS) This bit may be programmed at any time, regardless of the state of LOCK2. This bit is intended to be programmed when a module has been determined by the DSI Bus Master to be defective. Programming this bit after LOCK2 has been set will cause the device to respond to short word Read Acceleration Data commands with a zero response. Acceleration results are not affected by this bit when long word Read Acceleration Data commands are executed, however the Status (S) bit will be set in the response. 1 - Device responds to Read Acceleration Data command with zero value 0 - Device responds normally to Read Acceleration Data command 3.2.6.5 Device Address (AD3 - AD0) These bits define the pre-programmed DSI Bus device address. 3.3 OTP PROGRAMMING Two different methods of programming the eighty customer defined bits are supported. In test mode, these may be programmed in the same manner as factory programmed OTP bits. Additionally, the Read Write NVM DSI bus command may be used. Test mode programming operations are described in Appendix A.3. Read Write NVM command operation is described in Section 4.6.3. MMA81XXTKEG Sensors Freescale Semiconductor 15 SECTION 4 PHYSICAL LAYER AND PROTOCOL MMA81XXTKEG/MMA82XXTKEG family is compliant with the DSI Bus Standard, Version 2.0. MMA81XXTKEG/ MMA82XXTKEG is designed to be compatible with either DSI Version 2 or DSI Version 1.1 compliant bus masters. 4.1 DSI NETWORK PHYSICAL LAYER INTERFACE Refer to Section 3 of the DSI Bus Standard for information regarding the physical layer interface. 4.2 DSI NETWORK DATA LINK LAYER Refer to Section 4 of the DSI Bus Standard for information regarding the DSI network data link layer interface. Both standard and enhanced command structures are supported for short word and long word commands. 4.3 DSI BUS COMMANDS DSI Bus Commands which are recognized by MMA81XXTKEG and the MMA82XXTKEG are summarized in Table 4-1. Detailed descriptions of each supported command are described in subsequent sections of this document. If a CRC error is detected, or a reserved or unimplemented command is received, the device will not respond. Following all messages, MMA81XXTKEG and the MMA82XXTKEG disregards the DSI bus voltage level for approximately 18.5 μs. Within this time, all supported commands except Initialization and Reverse Initialization are guaranteed to be executed and the device will be ready for the next message. When the bus voltage falls below the signal high logic level (see Section 5) after the 18.5 μs period has elapsed, the device will respond as appropriate to a command sent to it in the previous message. Exactly one response is attempted; if a noise spike or corrupted transfer occurs, the response is not retried. If an Initialization or Reverse Initialization command is executed and the Bus Switch (BS) bit is set, MMA81XXTKEG and MMA82XXTKEG will disregard the bus voltage level for a nominal period of 180 μs. This interval allows for the bus voltage to recover following closure of the bus switch, while the hold capacitor of a downstream slave charges. Table 4-1 DSI Bus Command Summary Command Data Binary Size Hex Description C3 C2 C1 C0 D7 D6 D5 D4 D3 D2 D1 D0 0 0 0 0 $0 Initialization LW NV BS B1 B0 PA3 PA2 PA1 PA0 0 0 0 1 $1 0 0 1 0 $2 Request Status SW — — — — — — — — Read Acceleration Data SW — — — — — — — — 0 0 1 1 $3 Not Implemented N/A 0 1 0 0 $4 Request ID Information SW — — — 0 1 0 1 0 1 $5 Not Implemented N/A Not Applicable 1 0 $6 Not Implemented N/A Not Applicable 0 1 1 1 $7 Clear SW — — — 1 0 0 0 $8 Not Implemented N/A 1 0 0 1 $9 Read Write NVM LW RA3 RA2 RA1 RA0 RD3 RD2 RD1 RD0 1 0 1 0 $A Format Control LW R/W FA2 FA1 FA0 FD3 FD2 FD1 FD0 1 0 1 1 $B Read Register Data LW 0 0 0 0 RA3 RA2 RA1 RA0 1 1 0 0 $C Disable Self-Test Stimulus SW — — — — — — — — 1 1 0 1 $D Activate Self-Test Stimulus SW — — — — — — — — 1 1 1 0 $E Reserved N/A 1 1 1 1 $F Reverse Initialization LW PA2 PA1 PA0 Not Applicable — — — — — — — — — — Not Applicable Not Applicable NV BS B1 B0 PA3 Legend: BS: Bus Switch Control (0: open, 1: close) NV: Nonvolatile memory control (1: program NVM) PA3 - PA0: Device address assigned during Initialization or Reverse Initialization RA3 - RA0: Internal user data register address FA2 - FA0: Format register address MMA81XXTKEG 16 Sensors Freescale Semiconductor FD3 - FD0: Format register data content 4.4 COMMAND RESPONSE SUMMARIES The device incorporates an analog-to-digital converter which translates the low-pass filtered acceleration signal to a 10-bit binary value. The 10-bit digital result is referred to as AD9 through AD0 in the response tables which follow. 4.4.1 Short Word Response Summary Short word responses for all commands are summarized below. Detailed DSI command descriptions may be found in Section 4.5. Table 4-2 Short-Word Response Summary Command Hex Description Response D7 D6 D5 D4 D3 D2 D1 D0 AT0 S GF 1 0 0 $0 Initialization Not Applicable $1 Request Status $2 Read Acceleration Data $3 Not Implemented $4 Request ID Information $5 Not Implemented No Response $6 Not Implemented No Response $7 Clear No Response $8 Not Implemented No Response $9 Read/Write NVM Not Valid $A Format Control Not Valid $B Read Register Data Not Valid $C Disable Self-Test Stimulus NV U ST BS AT1 AT0 S GF $D Activate Self-Test Stimulus NV U ST BS AT1 AT0 S GF $E Reserved $F Reverse Initialization NV U ST BS AT1 See Section 4.5.4 No Response V2 V1 V0 0 0 No Response Not Valid Legend: AT1 - AT0: Attribute codes (see Section 4.5.1.3) NV: State of fuse program control bit BS: State of Bus Switch (0: open, 1: closed) S: Accelerometer status flag (1: internal error) ST: Self-Test flag (1: self-test active) U - Undervoltage condition V2 - V0: Version ID MMA81XXTKEG Sensors Freescale Semiconductor 17 4.4.2 Long Word Response Summary Long word responses for all commands are summarized below. Detailed DSI command descriptions may be found in Section 4.5. Table 4-3 Long-Word Response Summary Command Hex Description Response D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 $0 Initialization A3 A2 A1 A0 0 0 0 BF NV BS B1 B0 PA3 PA2 PA1 PA0 D3 D2 $1 Request Status A3 A2 A1 A0 0 0 0 0 NV U ST BS AT1 $2 Read Acceleration Data A3 A2 A1 A0 GF S $3 Not Implemented $4 Request ID Information A3 A2 A1 A0 0 0 $5 Not Implemented No Response $6 Not Implemented No Response $7 Clear No Response $8 Not Implemented No Response $9 Read/Write NVM A3 A2 A1 A0 $A Format Control A3 A2 A1 A0 AT0 D1 S D0 GF AD9 AD8 AD7 AD6 AD5 AD4 AD3 AD2 AD1 AD0 No Response 0 0 V2 V1 V0 0 0 1 0 0 See Section 4.6.3 0 1 1 0 R/W FA2 FA1 FA0 FD3 FD2 FD1 FD0 $B Read Register Data A3 A2 A1 A0 $C Disable Self-Test Stimulus A3 A2 A1 A0 RA3 RA2 RA1 RA0 RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 0 0 0 0 NV U ST BS AT1 AT0 S GF $D Activate Self-Test Stimulus A3 A2 A1 A0 0 0 0 0 NV U ST BS AT1 AT0 S GF $E Reserved $F Reverse Initialization BS B1 B0 PA3 PA2 PA1 PA0 No Response A3 A2 A1 A0 0 0 0 BF NV Legend: A3 - A0: Device address AD9 - AD0: 10-bit acceleration data result AT1 - AT0: Attribute codes (see Section 4.5.1.3) BF: Bus Fault flag (1: bus fault) BS: State of Bus Switch (0: open, 1: closed) FA2 - FA0: Format register address FD3 - FD0: Format register data content GF: Ground fault detected NV: State of fuse program control bit PA3 - PA0: Device address assigned during Initialization/Reverse Initialization RA3 - RA 0: Internal user data register address RD7 - RD0: Internal user data register contents R/W: Read/Write flag for Format Control Register access S: Accelerometer Status Flag (1: internal error) ST: Self-Test Flag (1: self-test active) U - Undervoltage condition V2 - V0: Version ID MMA81XXTKEG 18 Sensors Freescale Semiconductor 4.5 DSI COMMAND DETAIL Detailed descriptions of command formats and responses are provided in this section. 4.5.1 DSI COMMAND AND RESPONSE BIT DESCRIPTIONS The following abbreviations are used in the descriptions of DSI commands and responses. 4.5.1.1 DSI Device Address - (A3 - A0) DSI device address. This address will be set to the pre-programmed device address following reset, or zero if no pre-programmed address has been assigned. If zero, the device address may be assigned during initialization or reverse initialization. 4.5.1.2 Acceleration Data - (AD9 - AD0) Ten-bit acceleration result produced by the device. This value is returned by the Read Acceleration Data command, described in Section 4.5.4. 4.5.1.3 Attribute Code Bits (AT1, AT0) These bits indicate the contents of DEVCFG1 bits 1 and 0 in response to a Request Status, Activate Self-Test Stimulus or Disable Self-Test Stimulus command. Table 4-4 Attribute Code Bit Assignments 4.5.1.4 LOCK2 DEVGFG1[1] DEVGFG1[0] AT1 AT0 0 X X 1 0 1 0 0 0 0 0 1 0 1 1 0 1 0 1 1 1 1 Bank Select (B1, B0) These bits are assigned during initialization or reverse initialization to select specific fields within the customer accessible data registers. Bank selection affects Read/Write NVM command operation. Invalid combinations of B1 and B0 result in no response from the device to the associated initialization or reverse initialization command. Refer to Section 4.6.3 for further details regarding register programming and bank selection. 4.5.1.5 Bus Fault Bit (BF) This bit indicates the success or failure of the bus test which is performed as part of an Initialization or Reverse Initialization command. 1 - Bus fault detected 0 - Bus test passed 4.5.1.6 Bus Switch Control/Status Bit (BS) This bit controls the state of the bus switch during an Initialization or Reverse Initialization command. It also indicates the state of the bus switch in response to the Initialization, Request Status, Disable Self-Test Stimulus, Activate Self-Test Stimulus and Reverse Initialization commands. 1 - Close bus switch, or bus switch closed 0 - Leave bus switch open, or bus switch opened 4.5.1.7 Format Control Register Address (FA2 - FA0) This three-bit field selects one of eight format control registers. Format control registers are described in Section 4.6.4.3. 4.5.1.8 Format Register Data (FD3 - FD0) Contents of a format control register. This is the data to be written to the register by a Format Control command, or the contents read from the register in response to a Format Control command. MMA81XXTKEG Sensors Freescale Semiconductor 19 4.5.1.9 Ground Fault Flag (GF) If ground loss detection has been enabled and a ground fault condition is detected, this bit will be set in the response to Request Status, Read Acceleration Data, Disable Self-Test Stimulus or Activate Self-Test Stimulus commands. If ground loss detection is not enabled, this bit will always be read as a logic ‘0’ value. 1 - Ground fault condition detected 0 - Ground connection within specified limits, or ground loss detection disabled. 4.5.1.10 Nonvolatile Memory Program Control Bit (NV) This bit enables programming of customer-programmed OTP locations when set during an Initialization or Reverse Initialization command. Data to be programmed are transferred to the device during subsequent Read Write NVM commands. 1 - Enable OTP programming 0 - OTP programming circuitry disabled 4.5.1.11 Assigned Device Address (PA3 - PA0) This field contains the device address to be assigned during an Initialization or Reverse Initialization command. The address assigned is reported by the device in response to the Initialization or Reverse Initialization command. 4.5.1.12 Register Address (RA3 - RA0) This field determines the register associated with a Read Write NVM or Read Register Data command. The two Bank Select bits (B1, B0) are used to additionally specify a nibble or bit when a Read Write NVM command is executed. 4.5.1.13 Register Data (RD7 - RD0) RD3 - RD0 contain data to be written to an OTP location when a Read Write NVM command is executed if the NV bit is set. RD3 - RD0 contain the data read from the selected register in response to a Read Write NVM command if the NV bit is cleared. RD7 - RD0 indicate the contents of the selected register in response to a Read Register Data command. 4.5.1.14 Format Control Register Read/Write Bit (R/W) This bit controls the operation performed by a Format Control command. 1 - Write Format Control register selected by FA2 - FA0 0 - Read Format Control register unless global command 4.5.1.15 Accelerometer Status Flag (S) This bit provides a cumulative indication of the various error conditions which are monitored by the device. 1 - Either one or more error conditions have been detected and/or the internal Self-Test stimulus circuitry is active 0 - No error condition has been detected The following conditions will cause the status flag to be set: *Internal Self-Test stimulus circuitry is active OTP array parity fault OTP fuse threshold fault (partially-programmed fuse) Transient undervoltage condition Ground fault (if GLDE bit in DEVCFG2 is set) 4.5.1.16 Self-Test State (ST) This bit indicates whether internal self-test stimulus circuitry is active in response to Request Status, Disable Self-Test Stimulus and Activate Self-Test Stimulus commands. 1 - Self-Test stimulus active 0 - Self-Test stimulus disabled 4.5.1.17 Undervoltage Flag (U) This flag is set if the voltage at HCAP is below a specified threshold. Refer to Section 1.3.1 and Section 5 for further details. MMA81XXTKEG 20 Sensors Freescale Semiconductor 4.5.2 Initialization Command The initialization command conforms to the description provided in Section 6.2.1 of the DSI Bus Standard, Version 2.0. At powerup the device is fully compliant with the DSI 1.1 protocol. The initialization command must be transmitted as a DSI 1.1 compliant long command structure. Features of the DSI 2.0 protocol can not be accessed until a valid DSI 1.1 compliant initialization sequence is performed and the enhanced mode format registers are properly configured. Table 4-5 Initialization Command Structure Data Address Command CRC D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 C3 C2 C1 C0 NV BS B1 B0 PA3 PA2 PA1 PA0 A3 A2 A1 A0 0 0 0 0 4 bits Figure 4-1 illustrates the sequence of operations performed following negation of internal Power-On Reset (POR) and execution of a DSI Initialization command. Initialization commands are recognized only at BUSIN. The BUSOUT node is tested for a bus short to battery high voltage condition, and the Bus Fault (BF) flag set if an error condition is detected. If no bus fault condition is detected and the BS bit is set in the command structure, the bus switch will be closed. If the BS bit is set, the DSI bus voltage level is disregarded for approximately 180 μs following initialization to allow the hold capacitor on a downstream slave to charge. If the device has been pre-programmed, PA3 - PA0 and A3 - A0 must match the pre-programmed address. If no device address has been previously programmed into the OTP array, PA3 - PA0 contain the device address, while A3 - A0 must be zero. If any addressing condition is not met, the device address is not assigned, the bus switch will remain open and the device will not respond to the Initialization command. Table 4-6 Initialization Command Response Data CRC D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 0 0 0 BF NV BS B1 B0 A3 A2 A1 A0 4 bits In the response, bits D15 - D12 and D3 - D0 will contain the device address. If the device was unprogrammed when the initialization command was issued, the device address is assigned as the command executes. Both fields will contain the value PA3 - PA0 to indicate successful device address assignment. Initialization or reverse initialization commands which attempt to assign device address zero are ignored. MMA81XXTKEG Sensors Freescale Semiconductor 21 POR NEGATED LOAD REGISTERS FROM FUSE ARRAY INITIALIZATION COMMAND AT BUSIN? N N Y REVERSE INITIALIZATION COMMAND AT BUSOUT? N BS == 1? Y N Y BS == 1? ENABLE IRESP CURRENT DRIVE AT BUSOUT Y DELAY 10 μs ENABLE IRESP CURRENT DRIVE AT BUSIN MEASURE BUSOUT VOLTAGE DELAY 10 μs N VBUSOUT < VTHH? Y MEASURE BUSIN VOLTAGE SET BF FLAG SET BF FLAG N VBUSIN < VTHH? CLOSE BUS SWITCH Y CLOSE BUS SWITCH WAIT FOR NEXT DSI BUS COMMAND Figure 4-1. Initialization Sequence MMA81XXTKEG 22 Sensors Freescale Semiconductor 4.5.3 Request Status Command The Request Status command may be transmitted as either a DSI long command structure or a DSI short command structure of any length. The data field in the command structure is ignored but is included in the CRC calculation. No action is taken if this command is sent to the DSI Global Device Address. Table 4-1 Request Status Command Structure Address Command CRC A3 A2 A1 A0 C3 C2 C1 C0 A3 A2 A1 A0 0 0 0 1 0 to 8 bits Table 4-2 Short Response Structure - Request Status Command Response Response Length D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 NV U ST BS D3 D2 D1 D0 S GF 8 9 10 11 12 13 14 0 15 0 0 0 0 0 0 AT1 AT0 Table 4-3 Long Response Structure - Request Status Command Data CRC D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 0 0 0 0 NV U ST BS AT1 AT0 S GF 4.5.4 0 to 8 bits Read Acceleration Data Command The Read Acceleration Data command may be transmitted as either a DSI long command structure or a DSI short command structure of any length. The data field in the command structure is ignored but is included in the CRC calculation. No action is taken if this command is sent to the DSI Global Device Address. Table 4-4 Read Acceleration Data Command Structure Address Command CRC A3 A2 A1 A0 C3 C2 C1 C0 A3 A2 A1 A0 0 0 1 0 0 to 8 bits Table 4-5 Short Response Structure - Read Acceleration Data Command Response Length Response D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 8 AD9 AD8 AD7 AD6 AD5 AD4 AD3 AD2 9 AD9 AD8 AD7 AD6 AD5 AD4 AD3 AD2 AD1 MMA81XXTKEG Sensors Freescale Semiconductor 23 Table 4-5 Short Response Structure - Read Acceleration Data Command Response Response Length D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 10 11 12 13 14 DEVCFG1[1] 15 DEVCFG1[0] ST S GF AD9 AD8 AD7 AD6 AD5 AD4 AD3 AD2 AD1 AD0 Table 4-6 Long Response Structure - Read Acceleration Data Command Data CRC D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 GF S AD9 AD8 AD7 AD6 AD5 AD4 AD3 AD2 AD1 AD0 0 to 8 bits Data returned in response to a Read Acceleration Data command varies, as illustrated in Table 4-5 and Table 4-6. The result is also affected by the state of the self-test circuitry and internal parity. If the self-test circuitry is enabled, the ST bit will be set in data bit D12 of a short word response. If a transient undervoltage condition, parity fault, ground fault or device disable condition exists, the reserved data value of zero will be reported in response to a short word command structure to indicate that a fault condition has been detected. The data value is not affected by a fault condition when a long word response is reported, however the S and GF bits will be set as appropriate. If the self-test circuitry is active, acceleration data is reported regardless of parity faults. The Status (S) bit will be set in either short word or long word responses if a parity fault is detected. 4.5.4.1 ACCELERATION DATA REPRESENTATION Acceleration values may be determined from the 10-bit digital output (DV) as follows: a = sensitivity × (DV - 512) Sensitivity is determined by nominal full-scale range (FSR), linear range of digital values and a scaling factor to compensate for sensitivity error. The linear range of digital values for MMA81XXTKEG/MMA82XXTKEG is 1 to 1023. The digital value of 0 is reserved as an error indicator. For the linear ranges of digital values indicated, the nominal value of 1 LSB for each full-scale range is shown in the table below. Table 4-7 Nominal Sensitivity (10-bit data) Full-Scale Range (g) Nominal Sensitivity (g/digit) 250 0.61 150 0.366 100 0.244 50 0.122 40 0.0976 20 0.0488 MMA81XXTKEG 24 Sensors Freescale Semiconductor 4.6 ACCELERATION MEASUREMENT TIMING Upon verification of the CRC associated with a Read Acceleration Data command, MMA81XXTKEG/MMA82XXTKEG initiates an analog-to-digital conversion. The conversion occurs during the inter frame separation (IFS) and involves a delay during which the BUSIN line is allowed to stabilize, a sample period and finally the translation of the analog signal level to a digital result. 4.6.1 Request ID Information Command The Request ID Information command may be transmitted as either a DSI long command structure or a DSI short command structure of any length. The data field in the command structure is ignored but is included in the CRC calculation. No action is taken by MMA81XXTKEG/MMA82XXTKEG if this command is sent to the DSI Global Device Address. Table 4-8 Request ID Information Command Structure Address Command CRC A3 A2 A1 A0 C3 C2 C1 C0 A3 A2 A1 A0 0 1 0 0 0 to 8 bits Table 4-9 Short Response Structure - Request ID Information Command Response Response Length D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 V2 V1 V0 0 0 1 0 0 8 9 10 11 12 13 14 15 0 0 0 0 0 0 0 Table 4-10 Long Response Structure - Request ID Information Command Data CRC D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 0 0 0 0 V2 V1 V0 0 0 1 0 0 4.6.2 0 to 8 bits Clear Command The Clear command may be transmitted as either a DSI long command structure or a DSI short command structure of any length. The data field in the command structure is ignored but is included in the CRC calculation. Table 4-11 Clear Command Structure Address Command CRC A3 A2 A1 A0 C3 C2 C1 C0 A3 A2 A1 A0 0 1 1 1 0 to 8 bits When a Clear Command is successfully decoded and the address field matches either the assigned device address or the DSI Global Device Address, the bus switch is opened and the device undergoes a full reset operation. There is no response to the Clear Command. MMA81XXTKEG Sensors Freescale Semiconductor 25 4.6.3 Read/Write NVM Command The Read/Write NVM command must be transmitted as a DSI long command structure. No action is taken by MMA81XXTKEG/ MMA82XXTKEG if this command is sent to the DSI Global Device Address. Table 4-12 Read Write NVM Command Structure Data Address Command CRC D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 C3 C2 C1 C0 RA3 RA2 RA1 RA0 RD3 RD2 RD1 RD0 A3 A2 A1 A0 1 0 0 1 0 to 8 bits Table 4-13 Long Response Structure - Read/Write NVM Command (NV = 1) Data CRC D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 RA3 RA2 RA1 RA0 1 1 B1 B0 RD3 RD2 RD1 RD0 0 to 8 bits Table 4-14 Long Response Structure - Read/Write NVM Command (NV = 0) Data CRC D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 0 0 0 0 1 1 1 1 A3 A2 A1 A0 0 to 8 bits There is no response if the Read/Write NVM Command is received within a DSI short command structure. OTP data are accessed by fields, where a field is a combination of register address (RA3 - RA0) and bank select (B1, B0) bits. Bank select bits are assigned during an Initialization or Reverse Initialization command. Individual bits with predefined functions (the upper four bits of DEVCFG2) each have their own field address. The remaining OTP data are grouped into four-bit fields. Field addresses are shown in Table 4-15. The structure of the OTP array results in data being programmed in 16-bit groups. DEVCFG1 and DEVCFG2 are in the same group. As a result, a non-zero device address assigned during Initialization or Reverse Initialization will be permanently programmed into the OTP array when any field within the two device configuration bytes is programmed. To avoid programming a non-zero device address, ensure that device address 0 is assigned during Initialization or Reverse Initialization before programming any other bit(s) in DEVCFG1 or DEVCFG2. OTP programming operations occur when the Read/Write NVM command is executed after the NV bit has been set during a preceding Initialization or Reverse Initialization command. The minimum DSI Bus idle voltage must exceed 14 V when programming the OTP array. When this command is executed while the NV bit is cleared, the DSI device address will be returned regardless of the state of the register address and bank select bits. The Read Register Data command (described in Section 4.6.5) may be used to access the full range of customer accessible data. MMA81XXTKEG 26 Sensors Freescale Semiconductor Table 4-15 OTP Field Assignments Register Address Register Definition 1 DEVCFG1[3:0] User Defined 1 0 DEVCFG1[7:4] 0 0 DEVCFG2[7] LOCK2 0 1 DEVCFG2[3:0] DSI Bus Device Address 1 0 DEVCFG2[5] GLDE 1 1 DEVCFG2[6] PAR2 0 1 REG8[3:0] User Defined 1 0 REG8[7:4] 0 1 REG9[3:0] 1 0 REG9[7:4] 0 1 REGA[3:0] 1 0 REGA[7:4] 0 1 REGB[3:0] 1 0 REGB[7:4] 0 1 REGC[3:0] 1 0 REGC[7:4] 0 1 REGD[3:0] 1 0 REGD[7:4] 0 1 REGE[3:0] 1 0 REGE[7:4] 0 1 REGF[3:0] 1 0 REGF[7:4] 1 1 DEVCFG[4] RA3 RA2 RA1 RA0 B1 B0 0 1 1 0 0 0 4.6.4 Bank Select 1 1 1 1 0 0 0 1 0 0 1 1 0 1 0 1 0 1 1 1 1 0 0 1 1 0 1 1 1 1 0 1 1 1 1 User Defined User Defined User Defined User Defined User Defined User Defined User Defined DDIS Format Control Command The Format Control command must be transmitted as a DSI long command structure. No change to the format registers occurs if the Format Control Command is received within a DSI short command structure. If this command is sent to the DSI Global Device Address, the format registers are updated, however there is no response. The Format Control command conforms to the DSI 2.0 Specification. Table 4-16 Format Control Command Structure Data Address Command CRC D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 C3 C2 C1 C0 R/W FA2 FA1 FA0 FD3 FD2 FD1 FD0 A3 A2 A1 A0 1 0 1 0 4.6.4.1 0 to 8 bits Format Register Read/Write Control Bit (R/W) 1 - Write Format Control register selected by FA2 - FA0 0 - Read Format Control register unless global command MMA81XXTKEG Sensors Freescale Semiconductor 27 4.6.4.2 Format Control Register Selection (FA2 - FA0) This three-bit field selects one of eight format control registers. Format control registers are described in Section 4.6.4.3. Table 4-17 Long Response Structure - Format Control Command Data CRC D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 0 1 1 0 R/W FA2 FA1 FA0 FD3 FD2 FD1 FD0 0 to 8 bits There is no response if the Format Control Command is received within a DSI short command structure. 4.6.4.3 Format Control Registers The seven 4-bit format control registers defined in the DSI 2.0 Bus Specification are shown in Table 4-18 below. The default values assigned to each register following reset are indicated. Table 4-18 Format Control Registers Format Control Register Default Value Address Name Decimal FA2 FA1 FA0 FD3 FD2 FD1 FD0 CRC Polynomial - Low Nibble 0 0 0 0 0 0 0 1 CRC Polynomial - High Nibble 1 0 0 1 0 0 0 1 Seed - Low Nibble 2 0 1 0 1 0 1 0 Seed - High Nibble 3 0 1 1 0 0 0 0 CRC Length (0 to 8) 4 1 0 0 0 1 0 0 Short Word Data Length (8 to 15) 5 1 0 1 1 0 0 0 Reserved 6 1 1 0 0 0 0 0 Format Selection 7 1 1 1 0 0 0 0 The following restrictions apply to format control register operations, in accordance with the DSI 2.0 Bus Specification: • • • Attempting to write a value greater than eight to the CRC Length Register will cause the write to be ignored. The contents of the register will remain unchanged. Attempting to write a value less than eight to the Short Word Data Length register will cause the write to be ignored. The contents of the register will remain unchanged. The contents of the Format Selection register determine whether standard DSI values or the values contained in the remaining format control registers will be used. The values contained in the remaining format control registers become effective when this register is successfully written to ‘1111’. If the register is currently cleared, and one of the data bits FD3 - FD0 is not received as a logic ‘1’, the data in the register will remain all zeroes and the device will continue to use standard DSI format settings. If the register bits FD3 - FD0 are all set and one of the bits is received as a logic ‘0’ value, the data in the register will remain ‘1111’ and the values contained in the remaining format control registers will continue to be used. MMA81XXTKEG 28 Sensors Freescale Semiconductor 4.6.5 Read Register Data Command The Read Register Data command must be transmitted as a DSI long command structure. Table 4-19 Read Register Data Command Structure Data Address Command CRC D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 C3 C2 C1 C0 0 0 0 0 RA3 RA2 RA1 RA0 A3 A2 A1 A0 1 0 1 1 0 to 8 bits Table 4-20 Long Response Structure - Read Register Data Command Data CRC D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 RA3 RA2 RA1 RA0 RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 0 to 8 bits There is no response if the Read Register Data Command is received within a DSI short command structure or if this command is sent to the DSI Global Device Address. The sixteen registers shown in Table 3-1 may be accessed using this command. Register address combinations are listed below. Table 4-21 Read Register Data Command Address Assignment RA3 RA2 RA1 RA0 Register 0 0 0 0 SN0 0 0 0 1 SN1 0 0 1 0 SN2 0 0 1 1 SN3 0 1 0 0 TYPE 0 1 0 1 Reserved 0 1 1 0 DEVCFG1 0 1 1 1 DEVCFG2 1 0 0 0 REG-8 1 0 0 1 REG-9 1 0 1 0 REG-A 1 0 1 1 REG-B 1 1 0 0 REG-C 1 1 0 1 REG-D 1 1 1 0 REG-E 1 1 1 1 REG-F MMA81XXTKEG Sensors Freescale Semiconductor 29 4.6.6 Disable Self-Test Stimulus Command The Disable Self-Test Stimulus command may be transmitted as either a DSI long command structure or a DSI short command structure of any length. The data field in the command structure is ignored but is included in the CRC calculation. Table 4-22 Disable Self-Test Stimulus Command Structure Address Command CRC A3 A2 A1 A0 C3 C2 C1 C0 A3 A2 A1 A0 1 1 0 0 0 to 8 bits Table 4-23 Short Response Structure - Disable Self-Test Stimulus Command Response Response Length D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 NV U ST BS D3 D2 D1 D0 S GF 8 9 10 11 12 13 14 15 0 0 0 0 0 0 0 AT1 AT0 Table 4-24 Long Response Structure - Disable Self-Test Stimulus Command Data CRC D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 0 0 0 0 NV U ST BS AT1 AT0 S GF 0 to 8 bits This command will execute if either the device specific address or DSI global device address (address $0) is provided. A secondary function, self-test lockout, is activated when two consecutive Disable Self-Test Stimulus commands are received. Following self-test lockout, the internal self-test circuitry is disabled until a Clear command is received or the device undergoes power-on reset. 4.6.7 Enable Self-Test Stimulus Command The Enable Self-Test Stimulus command may be transmitted as either a DSI long command structure or a DSI short command structure of any length. The data field in the command structure is ignored but is included in the CRC calculation. No action is taken by the device if this command is sent to the DSI Global Device Address. Table 4-25 Enable Self-Test Stimulus Command Structure Address Command CRC A3 A2 A1 A0 C3 C2 C1 C0 A3 A2 A1 A0 1 1 0 1 0 to 8 bits MMA81XXTKEG 30 Sensors Freescale Semiconductor Table 4-26 Short Response Structure - Enable Self-Test Stimulus Command Response Response Length D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 NV U ST BS D3 D2 D1 D0 S GF 8 9 10 11 12 13 14 15 0 0 0 0 0 0 0 AT1 AT0 Table 4-27 Long Response Structure - Enable Self-Test Stimulus Command Data CRC D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 0 0 0 0 NV U ST BS AT1 AT0 S GF 0 to 8 bits If self-test locking has been activated, the ST bit will be cleared in the response from the device. Self-Test locking is described in Section 4.6.6. 4.6.8 Reverse Initialization Command The reverse initialization command conforms to the description provided in Section 6.2.1 of the DSI Bus Standard, Version 2.0. At power-up the device is fully compliant with the DSI 1.1 protocol. The initialization command must be transmitted as a DSI 1.1 compliant long command structure. Features of the DSI 2.0 protocol can not be accessed until a valid DSI 1.1 compliant initialization sequence is performed and the enhanced mode format registers are properly configured. Table 4-28 Reverse Initialization Command Structure Data Address Command CRC D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 C3 C2 C1 C0 NV BS B1 B0 PA3 PA2 PA1 PA0 A3 A2 A1 A0 1 1 1 1 4 bits Figure 4-1 illustrates the sequence of operations performed following negation of internal power-on reset (POR) and execution of a DSI Reverse Initialization command. Reverse Initialization commands are recognized only at BUSOUT. The BUSIN node is tested for a bus short to battery high voltage condition, and the bus fault (BF) flag set if an error condition is detected. If no bus fault condition is detected and the BS bit is set in the command structure, the bus switch will be closed. If the device has been pre-programmed, PA3 - PA0 and A3 - A0 must match the pre-programmed address. If no device address has been previously programmed into the OTP array, PA3 - PA0 contain the device address, while A3 - A0 must be zero. If any addressing condition is not met, the device address is not assigned, the bus switch will remain open and the device will not respond to the Reverse Initialization command. If the BS bit is set, the DSI bus voltage level is disregarded for approximately 180 μs following reverse initialization to allow hold capacitors on downstream slaves to charge. Table 4-29 Long Response Structure - Reverse Initialization Command Data CRC D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 0 0 0 BF NV BS B1 B0 A3 A2 A1 A0 4 bits In the response, bits D15 - D12 and D3 - D0 will contain the device address. If the device was unprogrammed when the reverse initialization command was issued, the device address is assigned as the command executes. Both fields will contain the value PA3 - PA0 to indicate successful device address assignment. Initialization or reverse initialization commands which attempt to assign device address zero are ignored. MMA81XXTKEG Sensors Freescale Semiconductor 31 SECTION 5 PERFORMANCE SPECIFICATIONS 5.1 MAXIMUM RATINGS Maximum ratings are the extreme limits to which the device can be exposed without permanently damaging it. The device contains circuitry to protect the inputs against damage from high static voltages; however, do not apply voltages higher than those shown in the table below. Table 5-1 Ref 1 2 Rating Supply Voltages HCAP BUSIN, BUSOUT 3 Voltage at Programming/Test Mode Entry pin 4 Voltage at CREG, DIN, CLK, CFIL, DOUT Symbol Value Unit VHCAP VBUS -0.3 to +40 -0.3 to +40 V V (3) (3) VPP/TEST -0.3 to +11 V (3) VIN -0.3 to +3.0 V (3) VGND -0.3 to +3.0 V (3) IIN IIN 400 200 mA mA (3) (3) I ±10 mA (3) gmax gmax gmax ±1400 ±950 ±2200 g g g (3) (3) (3) gpms ±1500 g (3) 13 Unpowered Shock (six sides, 0.5 ms duration) gshock ±2000 g (3) 14 Drop Shock (to concrete surface) hDROP 1.2 m (3) VESD VESD VESD ±2000 ±500 ±200 V V V (3) (3) (3) Tstg TJ -40 to +125 -40 to +150 °C °C (3) (3) 5 Voltage at VGND 6 7 BUSIN, BUSOUT, BUSRTN and HCAP Current Maximum duration 1 s Continuous 8 Current Drain per Pin Excluding VSS, BUSIN, BUSOUT, BUSRTN 9 10 11 Acceleration (without hitting internal g-cell stops) Z-axis g-cell X-axis g-cell (40g, 70g) X-axis g-cell (100g - 250g) 12 Powered Shock (six sides, 0.5 ms duration) 1. 2. 3. 4. 15 16 17 Electrostatic Discharge Human Body Model (HBM) Charge Device Model (CDM) Machine Model (MM) 18 19 Temperature Range Storage Junction Parameters tested 100% at final test. Parameters tested 100% at unit probe. Verified by characterization, not tested in production. (*) Indicates a customer critical characteristic or Freescale important characteristic. MMA81XXTKEG 32 Sensors Freescale Semiconductor 5.2 Ref 20 5.3 THERMAL CHARACTERISTICS Characteristic Thermal Resistance Symbol Min Typ Max Units θJA θJC — — — — 85 46 °C/W °C/W (3) (3) OPERATING RANGE The operating ratings are the limits normally expected in the application and define the range of operation. Ref Symbol Min Typ Max Units VHCAP VBUS VL 6.3 -0.3 — — VH 30 30 V V (1) (1) VLVD VLVR VLVH — — — — — 100 6.2 6.3 — V V mV (1) (1) (3) CREG Undervoltage Detection (see Figure 5-2) Undervoltage Detection Threshold 26 CREG Recovery Threshold 27 28 Hysteresis (VLVR - VLVD) VLVD VLVR VLVH — — — 2.25 2.35 100 — — — V V mV (3) (3) (3) 29 Test Mode Activation Voltage VTEST 4.5 — 10 V (3) VPP/TEST VBUS 7.5 14 8.0 — 8.5 30 V V (3) (3) IPROG — — 85 mA (3) TA TL -40 — TH +125 °C (6) 21 22 Characteristic Supply Voltage (Note 9) VHCAP (Note 5) BUSIN, BUSOUT VHCAP Undervoltage Detection (see Figure 5-1) Undervoltage Detection Threshold 23 VHCAP Recovery Threshold 24 25 Hysteresis (VLVR - VLVD) Programming Voltage 30 via SPI 31 via DSI 32 OTP Programming Current 33 Operating Temperature Range Standard Temperature Range 1. 2. 3. 4. 5. 6. Parameters tested 100% at final test. Parameters tested 100% at unit probe. Verified by characterization, not tested in production. (*) Indicates a customer critical characteristic or Freescale important characteristic. Minimum operating voltage may be reduced pending characterization. Device fully characterized at +105 °C and +125 °C. Production units tested +105 °C, with operation at +125 °C guaranteed through correlation with characterization results. 9. Maximum voltage characterized. Minimum voltage tested 100% at final test. Maximum voltage tested 100% to 24 V at final test. MMA81XXTKEG Sensors Freescale Semiconductor 33 5.4 ELECTRICAL CHARACTERISTICS The unit digit is defined to be 1 least significant bit (LSB) of the 10-bit digital value, or 1 LSB of the equivalent 8-bit value if explicitly stated. VL ≤ (VBUS - VSS) ≤ VH, VL ≤ (VHCAP - VSS) ≤ VH,TL ≤ TA ≤ TH, unless otherwise specified. . Ref Characteristic Min Typ Max Units * * * * * * SENS SENS SENS SENS SENS SENS — — — — — — 0.0488 0.0976 0.122 0.244 0.366 0.610 — — — — — — g/digit g/digit g/digit g/digit g/digit g/digit (7) (7) (7) (7) (7) (7) * * * * * * SENS SENS SENS SENS SENS SENS — — — — — — 20.1 10.0 8.02 4.01 2.67 1.60 — — — — — — mV/V/g mV/V/g mV/V/g mV/V/g mV/V/g mV/V/g (3) (3) (3) (3) (3) (3) * * ΔSENS ΔSENS -5 -7 0 0 +5 +7 % % (1) (1) * * OFF8 OFF8 OFF10 OFF10 122 116 488 464 128 128 512 512 134 140 536 560 digit digit digit digit (7) (7) (1) (1) FSR FSR FSR FSR FSR FSR 21.0 42.0 52.5 105 158 263 24.9 49.9 62.3 124.7 187 312 26.6 53.4 66.7 133 200 334 g g g g g g (3) (3) (3) (3) (3) (3) 46 47 Digital Output Sensitivity 20g Range 40g Range 50g Range 100g Range 150g Range 250g Range CFIL Output Sensitivity (TA = 25 °C) 20g Range 40g Range 50g Range 100g Range 150g Range 250g Range Sensitivity Error TA = 25 °C TL ≤ TA ≤ TH 48 49 50 51 Offset (measured in 0g orientation) TA = 25 °C (8-bit) TL ≤ TA ≤ TH (8-bit) TA = 25 °C (10-bit) TL ≤ TA ≤ TH (10-bit) 52 53 54 55 56 57 Full-Scale Range, including sensitivity and offset errors 20g Range 40g Range 50g Range 100g Range 150g Range 250g Range 58 59 60 Range of Output Normal (10-bit) Normal (8-bit) Fault RANGE RANGE FAULT 1 1 — — — 0 1023 255 — digit digit digit (3) (3) (8) 61 Nonlinearity Measured at CFIL output, TA = 25 °C NLOUT -1 0 +1 % (3) VCREG REGLINE REGLOAD 2.37 — 0.45 2.5 — — 2.63 6 2 V mV mV/mA (1) (3) (3) RR CREG ESR 60 0.9 — — — — — — 700 dB μF mΩ (3) (3) (3) 34 35 36 37 38 39 40 41 42 43 44 45 Internal Voltage Regulator Output Voltage Line regulation Load regulation (IREG < 6 mA) Ripple rejection (DC ≤ fRIPPLE ≤ 10 kHz, CREG ≥ 0.9 μF) 65 66 CREG capacitance 67 Effective series resistance, CREG capacitor 62 63 64 1. 2. 3. 4. 7. 8. Symbol Parameters tested 100% at final test. Parameters tested 100% at unit probe. Verified by characterization, not tested in production. (*) Indicates a customer critical characteristic or Freescale important characteristic. Tested 100% at 10-bit output. 8-bit value verified via scan. Functionality verified 100% via scan. MMA81XXTKEG 34 Sensors Freescale Semiconductor 5.5 ELECTRICAL CHARACTERISTICS (continued) VL ≤ (VBUS - VSS) ≤ VH, VL ≤ (VHCAP - VSS) ≤ VH,TL ≤ TA ≤ TH, unless otherwise specified. . Ref Characteristic Min Typ Max Units 68 69 Input Voltage LOW (CLK,DIN) HIGH (CLK,DIN) VIL VIH — 0.7xVCreg — — 0.3xVCreg — V V (3) (3) 70 71 Output Voltage (IOUT = 200 μA) LOW (DOUT) HIGH (DOUT) VOL VOH — VCreg- 0.1 — — VSS+ 0.1 — V V (3) (3) 72 73 74 Output Loading, CFIL pin (Note 10) Resistance to VCREG, VSS Capacitance to VCREG, VSS Output voltage range RLOAD CLOAD VOUT 50 — VSS + 50 mV — — — — 20 VCREG-50mV kΩ pF V (3) (3) (3) 75 Bus Switch Resistance * RSW — 4.0 8.0 Ω (1) 76 Rectifier Forward Resistance * RFWD — — 2.5 Ω (3) 77 Rectifier Leakage Current * IRLKG — — 100 μA (1) VRECT VRECT — — — — 1.0 1.2 V V (3) (3) VRECT VRECT — — — — 1.0 1.2 V V (1) (1) IBIAS IBIAS — — — — 100 20 mA μA (1) (1) 80 81 BUSIN or BUSOUT to HCAP Rectifier Voltage Drop (VBUS = 26 V) IBUSIN or IBUSOUT = -15 mA IBUSIN or IBUSOUT = -100 mA (VBUS = 7 V) IBUSIN or IBUSOUT = -15 mA IBUSIN or IBUSOUT = -100 mA 82 83 BUSIN + BUSOUT Bias Current VBUSIN or VBUSOUT = 8.0 V, VHCAP = 9.0 V VBUSIN or VBUSOUT = 0.5 V, VHCAP = 24 V 84 85 BUSIN and BUSOUT Logic Thresholds Signal Low Signal High * * VTHL VTHH 2.7 5.4 3.0 6.0 3.3 6.6 V V (1) (1) 86 87 BUSIN and BUSOUT Hysteresis Signal Frame * * VHYSS VHYSF 30 100 — — 90 300 mV mV (3) (3) 88 BUSIN + BUSOUT Response Current VBUSIN and/or VBUSOUT = 4.0 V IRESP 9.9 11 12.1 mA (1) IQ — — 7.5 mA (1) 90 Internal pull-down resistance CLK RPD 20 60 100 kΩ (2) 91 Internal pull-down resistance VPP/TEST RPD kΩ (2) μA kΩ (1) (1) 78 79 89 Quiescent Current 92 93 1. 2. 3. 4. 10. Symbol GND Loss Detect (with external 3 kΩ resistor) Measurement Current Detection Resistance * * * * * IGNDETC RGNDDETC 437 309 1 340 — 371 10 Parameters tested 100% at final test. Parameters tested 100% at unit probe. Verified by characterization, not tested in production. (*) Indicates a customer critical characteristic or Freescale important characteristic. The external circuit configuration shown in Section 1.3.6 is recommended. MMA81XXTKEG Sensors Freescale Semiconductor 35 5.6 ELECTRICAL CHARACTERISTICS (continued) VL ≤ (VBUS - VSS) ≤ VH, VL ≤ (VHCAP - VSS) ≤ VH,TL ≤ TA ≤ TH, unless otherwise specified. . Ref 94 95 96 97 Characteristic Min Typ Max Units nRMS nP-P — — — — 2 8 digit digit (3) (3) nRMS nP-P — — — — 2 7 digit digit (3) (3) VXY VXZ VYX VYZ -5 -5 -5 -5 — — — — +5 +5 +5 +5 % % % % (3) (3) (3) (3) INL DNL GAINERR OFST nRMS nP-P -2 -1 -1 -3 -1 -3 — — — — — — +2 +1 +1 +3 +1 +3 digit digit %FSR digit digit digit (3) (3) (2) (3) (3) (3) * * * * * * ΔDFLCT ΔDFLCT ΔDFLCT ΔDFLCT DDFLCT DDFLCT — — — — — — 246 123 98 49 82 49 — — — — — — digit digit digit digit digit digit * * * * ΔDFLCT ΔDFLCT ΔDFLCT ΔDFLCT — — — — 307 299 205 123 — — — — digit digit digit digit Total Noise (see Figure 5-3) 400 Hz, 4-pole filter, 20g range RMS, 100 samples P-P, 100 samples 180 Hz, 2-pole filter, 20g range RMS, 100 samples P-P, 100 samples 98 99 100 101 Cross-Axis Sensitivity X-axis, X-axis to Y-axis X-axis, X-axis to Z-axis Y-axis, Y-axis to X-axis Y-axis, Y-axis to Z-axis 102 103 104 105 106 107 Analog to digital converter Relative accuracy Differential nonlinearity Gain error Offset error (VIN = VCREG/2) Noise (RMS, 100 samples) Noise (peak) 108 109 110 111 112 113 Deflection (Self-Test Output - Offset, average of 30 samples, measured in 0g orientation, TA = 25° C) X-axis, 20g Range X-axis, 40g Range X-axis, 50g Range X-axis, 100g Range X-axis, 150g Range X-axis, 250g Range 114 115 116 117 Symbol Z-axis, 40g Range Z-axis, 100g Range Z-axis, 150g Range Z-axis, 250g Range (7) (7) (7) (7) (7) (7) (7) (7) (7) (7) 118 Self-Test deflection range, TA = 25 °C, measured in 0g orientation ΔDFLCT -10 — +10 % (1) 119 Self-Test deflection range, TL ≤ TA ≤ TH, measured in 0g orientation ΔDFLCT -20 — +20 % (1) 1. 2. 3. 4. 7. Parameters tested 100% at final test. Parameters tested 100% at unit probe. Verified by characterization, not tested in production. (*) Indicates a customer critical characteristic or Freescale important characteristic. Tested 100% at 10-bit output. 8-bit value verified via scan. MMA81XXTKEG 36 Sensors Freescale Semiconductor POR NEGATED POR ASSERTED VLVR VLVD VHCAP VLVH UV UV UNDERVOLTAGE tUVR NORMAL OPERATION RESUMES UV: UNDERVOLTAGE CONDITION EXISTS GND Figure 5-1. VHCAP Undervoltage Detection VCREG INTERNAL RESET IS INITIALLY ASSERTED UNTIL VCREG ≥ VLVR, AND THEREAFTER WHEN VCREG ≤ VLVD. VLVR VLVD VLVH LOW-VOLTAGE CONDITION DETECTED POR ASSERTED POR NEGATED NORMAL OPERATION RESUMES GND Figure 5-2. VCREG Undervoltage Detection MMA81XXTKEG Sensors Freescale Semiconductor 37 MASTER UUT DOH BUSIN BUSOUT N/C BUSRTN DOL DSI BUS CONFIGURATION D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 A3 A2 A1 A0 C3 C2 C1 C0 0 0 0 0 0 0 0 0 0 0 A3 A2 A1 A0 0 0 1 0 COMMAND FORMAT 90 μs 20 μs CMD 1 CMD 2 CMD 3 CMD 99 CMD 100 XXX XXX RESP 1 RESP 2 RESP 98 RESP 99 RESP 100 MEASUREMENT WINDOW (10910 μs) MEASUREMENT TIMING Figure 5-3. Total Noise Measurement Conditions MMA81XXTKEG 38 Sensors Freescale Semiconductor 5.7 CONTROL TIMING VL ≤ (VBUS - VSS) ≤ VH, VL ≤ (VHCAP - VSS) ≤ VH,TL ≤ TA ≤ TH, unless otherwise specified. Ref Characteristic Symbol Min Typ Max Units tUVR 0.95 1.0 1.05 ms (8) tSAMPLE tCONVERT tDELAY 4.28 7.13 2.85 4.5 7.5 3.0 4.73 7.88 3.15 μs μs μs (8) (8) (8) 120 VHCAP Undervoltage Reset Period (see Figure 5-1) VHCAP < VRA to POR assertion 121 122 123 Analog to digital converter (see Figure 5-4) Sample time Conversion time Delay following bus idle 124 BUSIN and BUSOUT response current transition 1.0 mA to 9.0 mA, 9.0 to 1.0 mA tITR 4.5 — 7.5 mA/μs (3) 125 Initialization to Bus Switch Closing tBS 89 — 138 μs (3) 126 Signal Bit Transition Time tBIT 5 — 200 μs (3) 127 Loss of Signal Reset Time Maximum time below frame threshold tTO — — 10 ms (8) 128 129 BUSIN or BUSOUT Timing to Response Current BUSIN or BUSOUT ≤ VTHL to IBUS ≥ 7 mA BUSIN or BUSOUT ≤ VTHH to IBUS ≤ 5 mA tRSPH tRSPL — — — — 3.0 3.0 μs μs (3) (3) tIFS 2 — — ms (3) tIFS tIFS tIFS 200 20 20 — — — — — — μs μs μs (3) (3) (3) 360 162 400 180 440 198 Hz Hz (1) (1) cycles ms (8) (8) 131 132 133 Interframe Separation Time (see Figure 5-5) Following Read Write NVM Command Following Initialization or Reverse Initialization BS = 1 BS = 0 Following other DSI bus commands 134 135 Low Pass Filter (4-pole, -3 db Rolloff Frequency) (2-pole, -3 db Rolloff Frequency) BWOUT BWOUT 136 137 Ground Loss Detection Filter Time Cycles of fOSC Time tGNDETC tGNDETC 138 139 140 Reset Recovery Time POR negated to Initialization Command POR negated to 180 Hz Data Valid POR negated to 400 Hz Data Valid 141 Internal Oscillator Frequency 142 143 Logic Duty Cycle Logic ‘0’ Logic ‘1’ 144 OTP Programming, SPI program control 130 1. 2. 3. 4. 8. — — * * 16384 4.096 tRESET tRESET tRESET — — — — 5.3 2.4 100 — — μs ms ms (8) (3) (3) fOSC 3.80 4.0 4.20 MHz (1) DCL DCH 10 60 33 67 40 90 % % (8) (8) tPROG — — 2 ms (8) Parameters tested 100% at final test. Parameters tested 100% at unit probe. Verified by characterization, not tested in production. (*) Indicates a customer critical characteristic or Freescale important characteristics. Functionality verified 100% via scan. Timing is directly determined by internal oscillator frequency. MMA81XXTKEG Sensors Freescale Semiconductor 39 5.8 CONTROL TIMING (continued) VL ≤ (VBUS - VSS) ≤ VH, VL ≤ (VHCAP - VSS) ≤ VH,TL ≤ TA ≤ TH, unless otherwise specified. Ref Characteristic Symbol Min Typ Max Units tCLK tDC tCDIN — — — — — — — 20 ns ns ns ns (3) (3) (3) (3) 145 146 147 148 SPI Timing (see Figure 5-6) CLK period DIN to CLK setup CLK to DIN hold CLK to DOUT tCDOUT 500 50 50 — 149 150 151 Sensing Element Resonant Frequency Z-axis g-cell X-axis medium-g g-cell (20-50g) X-axis high-g g-cell (100-250g) fGCELL fGCELL fGCELL — 11.2 18.0 22.0 12.8 20.6 — 15.3 24.2 kHz kHz kHz (3) (3) (3) 152 153 154 Sensing Element Rolloff Frequency (-3 db) Z-axis g-cell X-axis medium-g g-cell (20-50g) X-axis high-g g-cell (100-250g) BWGCELL BWGCELL BWGCELL — — — 1.58 19 32 — — — kHz kHz kHz (3) (3) (3) 155 156 Gain at Package Resonance Z-axis X-axis Q Q — — 10 12 — — kHz kHz (3) (3) 157 158 Package Resonance Z-axis X-axis f f — — 45 9.5 — — kHz kHz (3) (3) 1. 2. 3. 4. 8. Parameters tested 100% at final test. Parameters tested 100% at unit probe. Verified by characterization, not tested in production. (*) Indicates a customer critical characteristic or Freescale important characteristics. Functionality verified 100% via scan. Timing is directly determined by internal oscillator frequency. MMA81XXTKEG 40 Sensors Freescale Semiconductor BUSIN tSAMPLE tCONVERT tDELAY STABILIZATION S/H CONVERSION Figure 5-4. A-to-D Conversion Timing DSI BUS COMMAND BUSIN tIFS Figure 5-5. DSI Bus Interframe Timing tCLK CLK tDC tCDIN DIN/VGND tCDOUT DOUT DATA VALID Figure 5-6. Serial Interface Timing MMA81XXTKEG Sensors Freescale Semiconductor 41 APPENDIX A TEST MODE OPERATION Test mode is entered when certain conditions are satisfied after power is applied to the device. Communication with the device is conducted using the SPI when in test mode. Two test mode operations are of interest to the customer. These operations are described below. Test mode communication is conducted using the serial peripheral interface (SPI). A.1 SPI DATA TRANSFER A 16-bit SPI is available for data transfer when the voltage at VPP/TEST is raised above VTEST. Test mode is entered when the sequence of data values shown above are transferred following reset. See Figure A-4 for details of 16-bit SPI packet. The state of DIN is latched on the rising edge of CLK. DOUT changes on the falling edge of CLK. The interface conforms to CPHA = 0, CPOL = 0 operation for conventional SPI devices. A.2 ADC TEST MODE A special device configuration useful for evaluating the performance of the analog-to-digital convertor block is available. When selected, internal buffers which drive the CFIL pin and ADC input are disabled, and the input of the ADC is connected to the CFIL pin, as illustrated in Figure A-1. The following sequence of operations must be performed to enter ADC Test Mode. Refer to Appendix A.4 for details regarding register read and write operations. 1. Apply VHCAP to the HCAP pin. This may be accomplished through BUSIN if desired. 2. Apply VTEST to the VPP/TEST pin. 3. Transfer the data value $AA to device register address $30 via the SPI. 4. Transfer the data value $55 to device register address $30 via the SPI. 5. Transfer the data value $1D to device register address $30 via the SPI. Remove power or lower the voltage at VPP/TEST to exit ADC Test Mode. MMA81XXTKEG 42 Sensors Freescale Semiconductor REGULATOR TRIM HCAP BUSIN N/C N/C VSS VSS VSS BUSRTN 11 VOLTAGE REGULATOR INTERNAL SUPPLY VOLTAGE 13 9 3 12 CREG CREG BUSOUT 1 2 16 15 10 14 GROUND LOSS DETECTOR BANDGAP REFERENCE LOGIC COMMAND DECODE STATE MACHINE RESPONSE GENERATION OSCILLATOR SELFTEST TRIM OSC TRIM SELFTEST VOLTAGE 7 4 OTP PROGRAMMING INTERFACE 6 8 SELF-TEST ENABLE VGND/DIN VPP/TEST DOUT CLK A-TO-D CONVERTER g-CELL C-TO-V CONVERTER GAIN TRIM 5 LOW-PASS FILTER OFFSET TRIM CFIL TCS TRIM Figure A-1. ADC Test Mode Configuration MMA81XXTKEG Sensors Freescale Semiconductor 43 A.3 OTP PROGRAMMING OPERATIONS The ten customer-programmed OTP locations (DEVCFG0, DEVCFG1 and REG-8 through REG-F) may be programmed when the device is in test mode if the following sequence of operations is performed. Register access operations required for OTP programming are described in Appendix A.4. 1. Apply VHCAP to the HCAP pin. This may be accomplished through BUSIN if desired. 2. Apply VTEST to the VPP/TEST pin. 3. Write the desired data values to the two registers via the SPI. 4. Transfer the data value $AA to device register address $30 via the SPI. 5. Transfer the data value $55 to device register address $30 via the SPI. 6. Transfer the data value $C6 to device register address $30 via the SPI. 7. Write the data value $00 to address $20 via the SPI. This will enable write access to the fuse mirror registers. 8. Write register data to be programmed into fuse array. 9. Write the data value $05 to address $20 via the SPI. The automatic programming sequence is initiated by this write operation. 10. Delay a minimum of 32 μs to allow the programming sequence to begin. 11. Read data value from address $29 until bit 5 is set. 12. If bit 4 of value read from address $29 is set, the programming operation did not complete successfully. Bits which are unprogrammed may be programmed to a logic ‘1’ state. The device may be incrementally programmed if desired, however once a bit is programmed to a logic ‘1’ state, it may not be reset to logic ‘0’ in the OTP array. Once the LOCK2 bit has been set, no further changes to the OTP array are possible. Setting LOCK2 also enables parity detection when the device operates in normal mode. A.4 INTERNAL REGISTER ACCESS Using the DIN /VGND, CLK, and DOUT pins, each address location of MMA81XXTKEG/MMA82XXTKEG can be read and written from an external SPI interface shown in Figure A-2. The corresponding registers may be used to: • • • Program the OTP memory Read the OTP memory Access various internal signals of the MMA81XXTKEG/MMA82XXTKEG in Test mode CLK DOUT DIN/VGND SERIAL PERIPHERAL INTERFACE REGISTER ARRAY TO DIGITAL INTERFACE OTP ARRAY Figure A-2. OTP Interface Overview MMA81XXTKEG 44 Sensors Freescale Semiconductor A.4.1 Interface Data Bit Stream The 16-bit SPI serial data consists of 6 bits for a data address, 1 bit for a data direction, and 8 bits for the data to be transferred as shown below. BIT FUNCTION 15 14 13 12 11 10 9 8 A[5] A[4] A[3] A[2] A[1] A[0] RW ⎯ 7 6 5 4 3 2 1 0 D[7] D[6] D[5] D[4] D[3] D[2] D[1] D[0] Figure A-3. Serial Data Stream A[5:0] Register array location to be read or written. D[7:0] Register array data. This is the data to be transferred to the register array during write operations, or the data contained in the array at the associated address during read operations. RW Control of data direction during the clocking of D[7:0] data bits as follows: RW = 1 Register array write. D[7:0] are transferred into the register array during subsequent transitions of the CLK input. RW = 0 Register array read. Data are transferred from the register array during subsequent transitions of the CLK input. A.4.2 Register Array Read Operation Read operations are completed through16-bit transfers using the SPI as shown below. Data contained in the array at the associated address are presented at the DOUT pin during the 8th through 15th falling edges at the CLK input. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 CLK DIN/VP2 A[5] A[4] A[3] A[2] A[1] A[0] RW DOUT D[7] D[6] D[5] D[4] D[3] D[2] D[1] D[0] Figure A-4. Serial Data Timing, Register Array Read Operation Should the data transfer be corrupted by e.g., noise on the clock line, a device reset is required to restore the state of internal logic. MMA81XXTKEG Sensors Freescale Semiconductor 45 A.4.3 Register Array Write Operation A write operation is completed through the transfer of a 16-bit value using the SPI as shown in the diagram below. Data present at the DIN pin are transferred to the register at the associated address during the 9th through 16th rising edges at the CLK input. Contents of the register at the time the write operation is initiated are presented at the DOUT pin during the 8th through 15th falling edges of the CLK input. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 CLK DIN/VP2 A[5] A[4] A[3] A[2] A[1] A[0] RW DOUT D[7] D[6 D[5] D[4] D[3] D[2] D[1] D[0] D[7] D[6] D[5] D[4] D[3] D[2] D[1] D[0] Figure A-5. Serial Data Timing, Register Array Write Operation A.4.4 Internal Address Map Overview OTP data is transferred to internal registers during the first sixteen clock cycles following oscillator startup and negation of internal reset. When the device operates in test mode, OTP data in the mirror registers may be overwritten. Mirror register writes must be enabled by setting the SPI_WRITE_ENABLE bit (address $29[5]). This bit may be set by writing the value $0 to address $20. Internal register read and write operations are described in Section 3. MMA81XXTKEG 46 Sensors Freescale Semiconductor PACKAGE DIMENSIONS MMA81XXTKEG Sensors Freescale Semiconductor 47 PACKAGE DIMENSIONS MMA81XXTKEG 48 Sensors Freescale Semiconductor How to Reach Us: Home Page: www.freescale.com Web Support: http://www.freescale.com/support USA/Europe or Locations Not Listed: Freescale Semiconductor, Inc. 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