u-blox LISA-C2 Series Скачать руководство пользователя страница 43 | Manualshive

Страница: 43 / 103

background image

LISA-C2 series and FW75-C200 - System Integration Manual

UBX-13000620 - R21

Early Production Information

System description

Page 43 of 103

LISA-C200

C

1

C

2

54

SPK_N

53

SPK_P

GND

40

MIC_P

GND

Negative Analog IN

Positive Analog IN

Negative Analog OUT

Positive Analog OUT

Audio Device

Reference

Reference

39

MIC_N

LISA-C200

54

SPK_N

53

SPK_P

GND

40

MIC_P

GND

Analog IN

Audio Device

Reference

Reference

39

MIC_N

Analog OUT

C

3

C

4

R2

R1

R4

R3

Figure 23: Application circuits to connect the module to audio devices with proper differential or single-ended input/output

Reference

Description

Part Number – Manufacturer

C1, C2, C3, C4

10 µF Capacitor X5R 0603 5% 6.3 V

GRM188R60J106M – Murata

R1, R3

0

Ω

Resistor 0402 5% 0.1 W

RC0402JR-070RL – Yageo Phycomp

R2, R4

Not populated

Table 22: Connection to an analog audio device

1.11.2

Digital (PCM) Audio interface

The Digital Audio interface enables communication with an external codec to support hands-free applications;
linear, µ-law, and A-law codecs are supported.
LISA-C200 modules support PCM data format over a bidirectional 4-wire I2S digital audio interface. The modules
act as master only. The applicable pins are described in Table 23:

Name

Description

Remarks

PCM_SYNC

PCM word alignment

Module output (master)

PCM_DOUT

PCM transmit data

Module output

PCM_CLK

PCM clock

Module output (master)

PCM_DIN

PCM receive data

Module input

Table 23: Audio Interface pins for LISA-C200

«
...
41
42
43
44
45
...
»

Содержание LISA-C2 Series

Страница 1: ...ocument describes the features and the integration of u blox LISA C2 series FW75 C200 CDMA2000 1xRTT cellular modules The modules are complete and cost efficient CDMA solutions offering 153 kb s downl...

Страница 2: ...UBX TN 12077 FW75 C200 FW75 C200 22S 01 E0 V 05 00 02R UBX TN 12077 LISA C200 LISA C200 22S 01 E0 V 05 00 03R UBX TN 12077 LISA C200 LISA C200 03S 00 E0 S 06 00 07R UBX 13005454 LISA C200 LISA C200 2...

Страница 3: ...e It is not necessary to read it from the beginning to the end The following symbols are used to highlight important information within the manual An index finger points out key information pertaining...

Страница 4: ...and Reset Sequences 21 1 6 5 Key points to system functions 23 1 7 RF connection 24 1 8 SIM interface 25 1 9 Serial communication 25 1 9 1 Serial interfaces configuration 26 1 9 2 Asynchronous serial...

Страница 5: ...detection functionality 62 2 5 ESD immunity test precautions 63 2 5 1 General precautions 65 2 5 2 Antenna interface precautions 66 2 5 3 Module interfaces precautions 67 3 Features description 68 3 1...

Страница 6: ...g paste 87 4 2 2 Reflow soldering 87 4 2 3 Optical inspection 89 4 2 4 Cleaning 89 4 2 5 Repeated reflow soldering 89 4 2 6 Wave soldering 89 4 2 7 Hand soldering 89 4 2 8 Rework 89 4 2 9 Conformal co...

Страница 7: ...LISA C200 and FW75 C200 modems are US CDMA certified to support 1xRTT data speeds on US CDMA carriers Sprint Verizon and Aeris FW75 C200 is strictly a data modem for embedded solutions while LISA C20...

Страница 8: ...and Rx Tx path separation before connecting to the LNA and RF PA devices A separate shield compartment houses the 800 MHZ and 1900 MHZ RF power amplifiers This compartment provides high Tx signal isol...

Страница 9: ...ption Remarks VCC All VCC Module supply Module supply input V_INT FW75 C200 LISA C2 O O Digital I O Interfaces supply output Digital I O Interfaces supply output V_INT 2 85V typical generated by the m...

Страница 10: ...l DC blocking 0 1 F capacitor MIC_P MICP1 LISA C200 AUDIO I Differential analog audio input positive Differential analog microphone input Internal DC blocking 0 1 F capacitor SPK_P EPP2 LISA C200 AUDI...

Страница 11: ...Manual 3 The module automatically switches from active mode to idle mode whenever possible if power saving is enabled refer to u blox C2 series AT Commands Manual 3 AT UPSV The module wakes up from i...

Страница 12: ...esign utilizing a power efficient circuit topology Figure 2 and by power management software controlling the module s power saving mode Baseband Processor Switching Step Down u blox LISA C2 series and...

Страница 13: ...rformance shall be optimized when the nominal VCC voltage of 3 8 V DC is applied It is strongly suggested that a module be powered in design with a 3 8 V DC power supply VCC Name Description Remarks V...

Страница 14: ...dden momentary power loss then the supply to the LISA 200 VCC pin should go to 0V to power down the module In addition the falling voltage on the VCC pin must have a minimal of a 2 sec duration timed...

Страница 15: ...ing regulator with its output circuit must be capable of providing a voltage value to the VCC pins within the specified operating range and must be capable of delivering greater than 1 2 Amps for safe...

Страница 16: ...3 A MBRA340T3G ON Semiconductor L1 10 H Inductor 744066100 30 3 6 A 744066100 Wurth Electronics L2 1 H Inductor 7445601 20 8 6 A 7445601 Wurth Electronics R1 470 k Resistor 0402 5 0 1 W 2322 705 8747...

Страница 17: ...stor 0402 5 0 1 W RC0402JR 074K7L Yageo Phycomp R3 2 2 k Resistor 0402 5 0 1 W RC0402JR 072K2L Yageo Phycomp U1 LDO Linear Regulator ADJ 3 0 A LT1764AEQ PBF Linear Technology Table 7 Suggested compone...

Страница 18: ...as possible in order to minimize power losses Three 3 or five 4 pins are allocated for VCC supply Another seven pins are designated for GND connection Even if all the VCC pins and all the GND pins are...

Страница 19: ...on when the voltage rises up to the VCC operating range minimum limit 3 4 V See LISA C2 series Data Sheet 1 or the FW75 C200 Data Sheet 2 provided that the PWR_ON pin is permanently low when VCC is ap...

Страница 20: ...alling edge on the PWR_ON pin After the detection of a start up event all the digital pins of the module are held in tri state until all the internal LDO voltage regulators are turned on in a defined...

Страница 21: ...module reset can be performed by AT CFUN command more details in u blox C2 series AT Commands Manual 3 in this case an internal or software reset is performed causing an asynchronous reset of the bas...

Страница 22: ...gh 50 ms 350 ms 3 s All interfaces are configured 0 ms 200 ms 10 s Tasks loaded Figure 8 Module power up timing and sequence of supply and signals 1 6 4 2 Power on using VCC method Pull PWR_ON pin low...

Страница 23: ...such a case wait 20 seconds after issuing the command and if OK has yet to be returned then as a last option perform either one of these actions Apply a hard reset using asserting RESET_N low for 300...

Страница 24: ...module to be powered on for a minimal of 10 sec before apply this reset method 2 Do allow enough time between each reset attempt with the RESET_N pin method Control pins Driving pulling RESET_N high...

Страница 25: ...the ITU T V 24 Recommendation 5 A customer application processor connected to the module through one of the interfaces represents the data terminal equipment DTE All the interfaces listed above are c...

Страница 26: ...th CMOS compatible signal levels 0 V for low data bit or ON state and 1 8 2 8 V for high data bit or OFF state One external voltage translator e g Maxim MAX13234E could be used to provide RS 232 5 lin...

Страница 27: ...reason for the difference is that CDMA technology does not support multiple transport types circuit switched and packet switched at the same time where GSM UMTS HSPA does support them The RI line is...

Страница 28: ...nd C200 22S 01 and onwards In comparison to USB the UART power saving implementation presents a better power consumption for this purpose By default the power saving mode is disabled In order to force...

Страница 29: ...consumption profile during cyclic idle active mode power saving disabled 1 9 2 3 UART application circuits The u blox C2 series family provides a 5 wire UART TxD RxD RTS CTS and RI the application ci...

Страница 30: ...DIR1 DIR3 OE B2 A2 B4 A4 DIR4 DIR2 Figure 15 UART interface application circuit with complete V 24 link in DTE DCE serial communication 3 0 V DTE Reference Description Part Number Manufacturer C1 C2...

Страница 31: ...he modem from ever resetting or powering up or down properly 1 9 3 USB interface LISA C200 and FW75 C200 modules provide a full speed USB interface at 12 Mb s compliant with the Universal Serial Bus R...

Страница 32: ...onnection of the USB cable or suspension by the USB host will allow the module to enter power save mode The module s current drops to the expected 2mA when then USB port is disconnected or the host go...

Страница 33: ...ed by the Universal Serial Bus Revision 2 0 specification 10 are part of the USB pad driver and do not need to be externally provided External series resistors on pins USB_D and USB_D as required by t...

Страница 34: ...sferring various kinds of data such as SMS PSD AT commands in general This permits for example SMS to be transferred to the DTE when a data connection is in progress The following virtual channels are...

Страница 35: ...on the module they must be mounted externally Resistor values must conform to the I 2 C bus specifications 11 If a LISA C module is connected by the DDC I 2 C bus to a u blox GNSS receiver only one d...

Страница 36: ...PS data ready function must be connected to the data ready output of the u blox GNSS receiver i e the pin TxD1 of the u blox GNSS receiver on the application board The GPS data ready function provides...

Страница 37: ...tor 0402 5 0 1 W RC0402JR 074K7L Yageo Phycomp R3 47 k Resistor 0402 5 0 1 W RC0402JR 0747KL Yageo Phycomp U1 Voltage Regulator for GNSS Receiver See GNSS Receiver Hardware Integration Manual Table 18...

Страница 38: ...0402 5 0 1 W RC0402JR 07200KL Yageo Phycomp C2 C3 C4 C5 100 nF Capacitor Ceramic X5R 0402 10 10V GRM155R71C104KA01 Murata U1 C1 Voltage Regulator for GNSS Receiver and relative output bypass capacito...

Страница 39: ...olled by the dedicated AT command USPM For LISA C200 refer to u blox C2 series AT Commands Manual 3 This command allows setting the audio path mode composed by the uplink audio path and the downlink a...

Страница 40: ...ectly connected to a headset earpiece or handset earpiece but is not able to drive an 8 speaker Warning excessive sound pressure from headphones can cause hearing loss Name Description Remarks MIC_P D...

Страница 41: ...point C 4 SPK L2 MIC Speaker Connector OUT IN GN D VMAIN U2 OUT IN C 8 C 9 R 5 R 6 VDD C11 C10 LISA C200 Audio Amplifier J1 J2 VMAIN C 7 Figure 22 Hands free mode application circuit Reference Descrip...

Страница 42: ...uency depending on both the values of capacitor and on the input impedance of the external audio device For example in case of differential input impedance of 600 the two 10 F capacitors will set the...

Страница 43: ...ufacturer C1 C2 C3 C4 10 F Capacitor X5R 0603 5 6 3 V GRM188R60J106M Murata R1 R3 0 Resistor 0402 5 0 1 W RC0402JR 070RL Yageo Phycomp R2 R4 Not populated Table 22 Connection to an analog audio device...

Страница 44: ...are available in both uplink and downlink direction Configure using AT commands Refer to the u blox AT Commands Manual 3 AT UI2S command for possible combinations of connection and settings 1 11 2 1 P...

Страница 45: ...pport biasing of level shifter ASICs A problem can result with certain level shifter interface buffers which can back feed voltage to the V_INT line preventing the modem from powering off and or reset...

Страница 46: ...cellular module from idle mode when the u blox GNSS receiver is ready to send data via the DDC I2C interface this is possible if the parameter mode of AT UGPS command is set to 1 and the parameter GPS...

Страница 47: ...Pad disabled mode can be provided on more than one pin per time it is possible to simultaneously set the same mode on another pin also on all the GPIOs The pin configured to provide the Pad disabled...

Страница 48: ...n the external reset is forced low and during the module power on sequence at least for 3 s after the start up event to avoid latch up of circuits and allow a proper boot of the module If the external...

Страница 49: ...1 W Various manufacturers U1 Voltage Regulator for GNSS Receiver See GNSS Module Hardware Integration Manual R2 4 7 k Resistor 0402 5 0 1 W Various manufacturers R5 10 k Resistor 0402 5 0 1 W Various...

Страница 50: ...00nF LISA C200 VCC VCC VCC VBUS D D GND VUSB_DE T USB_D USB_D GND 100nF GND ANT Antenna Connection LISA C200 SMT PAD DTE LISA 1 8V USB 2 0 Host GPIO1 3V8 RESET_N Ferrite Bead 47pF Application Processo...

Страница 51: ...GND VUSB_DE T USB_D USB_D GND 100nF GND ANT Main Antenna Connection FW75 C200 U FL Connector DTE FW75 2 8V USB 2 0 Host Status 3V8 Status Indicator HW_SHUTDOWN Ferrite Bead 47pF Application Processor...

Страница 52: ...s made to this device that are not expressly approved by u blox could void the user s authority to operate the equipment Manufacturers of mobile or fixed devices incorporating the LISA C200 and FW75 C...

Страница 53: ...Insert the suggested low capacitance ESD protection and passive filtering parts on each SIM signal Check UART signals direction since the signal names follow the ITU T V 24 Recommendation 5 Provide ap...

Страница 54: ...ennas 2 2 1 FW75 C200 modem connector Manufacturer Series Name Part No Specification Description Remarks Molex SlimStack 52991 0808 PS 54 167 002 Receptacle 80 pins 0 50mm pitch 4mm stacking height We...

Страница 55: ...molex com Drawing 734120110_sd pdf mechanical land pattern and reel specifications Data sheet 0734120110_RF_COAX_CONNECTORS pdf Table 28 FW75 C200 antenna connector Figure 29 FW75 C200 antenna connec...

Страница 56: ...Layout Avoid coupling with noisy signals Audio Inputs MIC_P MIC_N Audio Outputs SPK_P SPK_N 5th Ground GND Careful Layout Provide proper grounding 6th Sensitive Pin Careful Layout Avoid coupling with...

Страница 57: ...modules suggested footprint and paste mask To improve the wetting of the half vias reduce the amount of solder paste under the module and increase the volume outside of the module by defining the dime...

Страница 58: ...gn In Page 58 of 103 33 2 mm 11 85 mm 22 4 mm 5 3 mm 5 25 mm 1 4 mm 1 0 mm PIN 1 LISA C2 bottom side through module view Exposed GND on LISA C2 module bottom layer Signals keep out area on application...

Страница 59: ...uidelines suggested by antenna manufacturer Patch like antenna better suited for integration in compact designs e g mobile phone These are mostly custom designs where the exact definition of the PCB a...

Страница 60: ...11 indicates which portion of the power is delivered to antenna and which portion is reflected by the antenna back to the module output A good antenna should have an S11 below 10 dB over the entire fr...

Страница 61: ...tuned half wavelength dipole green purple and a penta band internal antenna yellow cyan The half lambda dipole tuned at 900 MHz is known and has good radiation performance both for gain and directivi...

Страница 62: ...ulting DC voltage to evaluate the resistance from ANT pad to GND The antenna detection is forced by the UANTR AT command refer to the u blox LISA C200 AT Commands Manual 3 for more details on how to a...

Страница 63: ...s below the measurement range minimum limit 1 k will highlight a short to GND at antenna or along the RF cable Measurement inside the valid measurement range and outside the expected range may indicat...

Страница 64: ...test results and applicability are reported in Table 33 according to test requirements 13 14 and 15 Category Application Immunity Level Contact Discharge to coupling planes indirect contact discharge...

Страница 65: ...mmended to keep the connection line to HW_SHUTDOWN as short as possible RESET_N pin LISA C200 only Sensitive interface is the reset line RESET_N pin A 47 pF bypass capacitor e g Murata GRM1555C1H470JA...

Страница 66: ...he device insulating enclosure avoids air discharge up to 8 kV 8 kV to the antenna interface no further precautions to ESD immunity test should be needed If the device implements an external antenna a...

Страница 67: ...d to be a port as defined in 13 Depending on applicability and in order to satisfy ESD immunity test requirements and ESD category level pins connected to the port should be protected up to 4 kV 4 kV...

Страница 68: ...y LISA C200 from version 04S 24S onwards LISA C200 modules support File Transfer Protocol functionalities via AT commands Files are read and stored in the local file system of the module Alternatively...

Страница 69: ...k with a base station or simulator The user can activate the test interface using the UTEST AT command to set the cellular module into these test modes Transmit mode to transmit a CDMA signal selectin...

Страница 70: ...TEST 2 command tests the receiving power level This measurement of power level can be done using the following syntax AT UTEST 2 par1 par2 par3 par1 par2 par3 are command parameters that can optionall...

Страница 71: ...onverted Example If you measure a receive channel 384 at 881 52 MHz band class 0 then set the signal generator at 881 49 MHz or 881 55 MHz If you set the signal generate at 881 52 MHz then utest may n...

Страница 72: ...signal is 5 dBm within tolerances Max output power levels vary between different firmware versions See u blox C2 series AT Commands Manual 3 for max power output levels corresponding to the various fi...

Страница 73: ...n is changed updating the parameters with the another AT UTEST 3 command Tx path test should be performed with spectrum analyzer connected to the antenna port It should be tuned to the center frequenc...

Страница 74: ...ersion is presently loaded in the module If the default PRL from the factory has changed the RTN command does not restore the PRL to the original factory version that it came with The MIP Profile is s...

Страница 75: ...ice performs a radio reset to load the new PRL The device will not have service for approximately 10 seconds after the PRL commit 3 5 2 5 Firmware update Sprint requires that OMA Clients support firmw...

Страница 76: ...ion 2 Client initiated PRL update 3 Client initiated FUMO 3 5 2 7 Session establishment Device management sessions can be established by the OMA DM Server using a Notification Initiation Alert NIA The...

Страница 77: ...lient initiated attempts will fail if an OMA DM session is already in progress 3 5 2 8 Best practices Host applications should not initiate data calls or power down cycle the module while an OMA DM se...

Страница 78: ...hould be 1 Check for DC values AT MDN Returns 000000XXXX AT MSID Returns 000000XXXX AT QCMIPGETP 1 Returns 000000XXXX sprintpcs com 2 Check for UOMASTAT URC messages 3 Allow 45 seconds from the C200 d...

Страница 79: ...00000 MIN OK Program the MIN Post Activation Validation Optional These optional steps may be performed to confirm that the module has been correctly programmed Step AT Command Response Comment 02 AT M...

Страница 80: ...visioning attempt Access to the AT Command interface through a COM port is required 3 5 5 2 Conversion steps The LISA C200 module can be migrated to USCC mode using UUSCELL 3 AT command Once in USCC m...

Страница 81: ...es AT Commands Manual 3 for more details The Xmodem protocol is used for downloading the new firmware image via a terminal application Firmware authenticity verification is performed via a security si...

Страница 82: ...s Manual 3 LISA C modules act as a stand alone AssistNow client making AssistNow available with no additional requirements for resources or software integration on an external host micro controller Fu...

Страница 83: ...s the estimated position based on the CellLocate TM database For AT command details see u blox C2 series AT Commands Manual 3 The CellLocate TM database is compiled from the position of devices which...

Страница 84: ...ces can be triggered to provide their current position using either a u blox GNSS receiver or the position estimated from CellLocate TM The choice depends on which positioning method provides the best...

Страница 85: ...k using the UPLAYFILE command During playback if there is an incoming voice call or if a call is terminated during playback then the playback instance will stop and will not resume Playback can be ini...

Страница 86: ...rvice GPIO output is low Registered Home Network CDMA Indicates registered with home CDMA network full or limited service GPIO cyclic output sequence High for 100ms Low for 2sec Registered Roaming CDM...

Страница 87: ...fication 95 5 Sn 3 9 Ag 0 6 Cu 95 5 Tin 3 9 Silver 0 6 Copper 95 5 Sn 4 0 Ag 0 5 Cu 95 5 Tin 4 0 Silver 0 5 Copper Melting Temperature 217 C Stencil Thickness 150 m for base boards The final choice of...

Страница 88: ...ids negative metallurgical effects solder becomes more brittle of the solder and possible mechanical tensions in the products Controlled cooling helps to achieve bright solder fillets with a good shap...

Страница 89: ...step after the soldering 4 2 5 Repeated reflow soldering Only a single reflow soldering process is encouraged for boards with a LISA C module populated on it The reason for this is the risk of the mo...

Страница 90: ...g ground cables wick or other forms of metal strips directly onto the EMI covers is done at the customer s own risk The numerous ground pins should be sufficient to provide optimum immunity to interfe...

Страница 91: ...t Ready DTE Data Terminal Equipment DTM Dual Transfer Mode DTR Data Terminal Ready EBU External Bus Interface Unit CDMA CODE Division Multiple Access FDD Frequency Division Duplex FEM Front End Module...

Страница 92: ...ency Modulation PMU Power Management Unit RF Radio Frequency RI Ring Indicator RTC Real Time Clock RTS Request To Send RUIM R UIM Removable User Identity Module card that extends a GSM SIM card for CD...

Страница 93: ...VD on LISA C200 modules and doesn t provide supply for Real Time Clock V_BCKP as on LISA U series modules Check the application circuit of pin 5 On LISA C200 this RSVD pin may be connected to GND for...

Страница 94: ...ayer See the Hardware migration section in this appendix for further details Check LISA C200 series software requirements Check the AT commands supported by LISA C200 via UART and USB serial interface...

Страница 95: ...applying VCC supply but the module switches on if the PWR_ON input pin is permanently low when VCC is applied The ANT pin of LISA C200 has 50 nominal characteristic impedance and must be connected to...

Страница 96: ...patible with LISA U120 and LISA U130 but the other LISA U series modules don t provide the same functionality on the paired pins 39 40 and 53 54 LISA C200 provides a PCM digital audio interface PCM_SY...

Страница 97: ...10 RI UART RI Output RI UART RI Output Compatible Circuit 125 RI in ITU T V 24 RI behavior different Refer to section 1 9 2 1 RI Signal Behavior 11 DCD UART DCD output RSVD RESERVED pin Tri stated wi...

Страница 98: ...SA U120 LISA U130 I2S1_TXD GPIO7 RESERVED pin 41 I2S_WA RSVD I2 S word alignment RESERVED pin PCM_SYN C PCM Digital Sync Migration from LISA U120 LISA U130 LISA U2x0 01 is possible according to extern...

Страница 99: ...ND Ground 61 VCC Module supply input VCC Module supply input LISA C200 VCC range 3 4 V to 4 2 V Switch on if PWR_ON is low when VCC is applied 62 VCC Module supply input VCC Module supply input LISA C...

Страница 100: ...a on the top layer of the application board below LISA U series modules 33 2 mm 11 85 mm 22 4 mm 5 3 mm 5 25 mm 1 4 mm 1 0 mm PIN 1 LISA C2 bottom side through module view Exposed GND on LISA C2 modul...

Страница 101: ...0 specification http www usb org developers docs 11 I2C Bus Specification Version 2 1 Philips Semiconductors January 2000 http www nxp com acrobat_download literature 9398 39340011_21 pdf 12 GPS Imple...

Страница 102: ...sses clee Changed Digital PCM Audio interface section to clarify I2S interface supports PCM data format Added Appendix B Migration from LISA U to LISA C200 Added 2 4 3 Antenna detection functionality...

Страница 103: ...rt support_ap u blox com Regional Office China Beijing Phone 86 10 68 133 545 E mail info_cn u blox com Support support_cn u blox com Regional Office China Chongqing Phone 86 23 6815 1588 E mail info_...

Отзывы:

Нет отзывов

Похожие инструкции для LISA-C2 Series

Бренд: ABB Страницы: 2

Бренд: Falcon Страницы: 3

Бренд: VAT Страницы: 29

Бренд: Balboa Instruments Страницы: 19

Бренд: Caen Страницы: 20

Бренд: D+H Страницы: 14

Бренд: Watts Страницы: 12

Бренд: Lancom Страницы: 8

Бренд: Mackie Страницы: 4

Бренд: u-blox Страницы: 28

Бренд: µ-Dimension Страницы: 48

Бренд: µ-Dimension Страницы: 2

GA Industries 930-DT

Бренд: Vag Страницы: 4

SensoTimer ST6 Duo eco!ogic

Бренд: Kärcher Страницы: 96

Бренд: D+H Страницы: 2

Бренд: Tenpilot Страницы: 2

Бренд: M-system Страницы: 7

Бренд: Texecom Страницы: 21

Бренды по названию

0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Популярные бренды

Загрузить еще бренды