MIT Wake-up Call SystemRuby PaiSurapap RayanakornAudrey RoyFeatures Security PIN- Each user is assigned a PIN associated with his telephone number- When a user calls in, the system verifies his PIN before allowing the user to proceed to the menu. Menu Options- Request wakeup call- Cancel requested wakeup call- Check scheduled requests for his phone number- Hear the system time to synchronize with the user’s watchBasic Block DiagramPhone Interface Functions detect incoming call pick up/hang up phone dial numbers detect/interpret dialed numbers send prerecorded audio over phone linePhone Terminology loop: twisted wire pair connection between phone and central office individual wires: tip and ringPhone Dialing Two types: pulse and tone Our system uses tone each digit dialed generates two tones (frequencies) also called dual tone multi frequency (DTMF)Phone Interface: MH88437 Data Access Arrangement Chip provides complete interface between audio/data transmission equipment and phone line Tip and Ring connections Functions: detect incoming call pick up/hang up phone send prerecorded audioPhone Interface: MT8889C DTMF transceiver convert binary digit to DTMF (outgoing call) convert DTMF to binary digit (incoming data)Audio Overview Record Mode:- Takes audio input from microphone- Samples the analog input - Store the samples in RAM- Store the samples in ROM by creating specification file from data in RAM Playback Mode:- Retrieves digitized samples from ROM upon requests from audio major FSM- Converts it to analog outputs- Amplifies and sends to the speakerRecord Mode – Audio Path The AC97 Controller controls the codec chip by supplying frames to the codec at rate 48,000 frames/sec. A frame consists of 13 slots (1 tag slot, and 12 data slots). One 18-bit digitized sample is received per an incoming frame to the AC97 controllerGainADC48 kHzMic (Analog input)Codec Chip LM4550AC97 Controller18 18Downsample12 kHz8RAM8Create specification file (CGF file)ROMControl signalsPlayback Mode: Interface with Control Unit Waits for the enable signal msg_reg from Major FSM Plays 8-bit voice messages according to the input signal msg_no Outputs msg_donesignal to notify Major FSM that the playback has finishedCONTROL MAJOR FSMmsg_reqmsg_nomsg_doneAUDIO FSMaudio6(Phone interface)Audio Path – Playback Mode Digitized samples in ROM are upsampled to match with the sampling rate of the codec by replicating the same sample 4 times ROM8Upsample48kHzAC97 Controller8DAC 48 kHzGainPhone interfaceCodec Chip LM4550Phone Number/PIN LUT810787619124438994468752660089158834357956407PIN #PHONE #• Each phone # has a unique PIN #• PIN # is preassignedTime Unit Holds the current system time Extension of the behavioral 1 second timer in Problem Set 2 Stored as month, day, time04 25 23:40 Sends output to Request Memory UnitRequest Memory Unit Combined with the Time Unit, it acts as the timer for every wake-up call Receives wake-up requests such as:Wake-up call for: 04 26 07:30PIN #: 9876 Collects requests in memory Sends ‘call’ signals at the appropriate timesRequest Memory Unit Requests are stored in a RAM, sorted by priority438504 26 07:50843004 26 10:12032104 26 10:00438504 26 09:45110304 26 08:45192904 26 08:30987604 26 07:30PIN #EVENT {month, day, time}20 bits 14 bitsRequest Memory Unit 3 basic operations: Store a new wake-up request As time passes, retrieve and send the request(s) that are ready for calling Cancel wake-up requests for a particular personStoring a Wake-up RequestControlUnitRequest Memory Unitstorestore_ackstore_event{month, day,time, PIN #}Control Unit sends the new request data & a store signalStoring a Wake-up Request438504 26 07:50843004 26 10:12032104 26 10:00438504 26 09:45110304 26 08:45192904 26 08:30987604 26 07:30PIN #EVENT {month, day, time}000404 26 08:00New requestmust be inserted hereStoring a Wake-up Request438504 26 07:50843004 26 10:12032104 26 10:00438504 26 09:45110304 26 08:45192904 26 08:30987604 26 07:30PIN #EVENT {month, day, time}000404 26 08:00Requests after insertion pointget shifted downStoring a Wake-up Request000404 26 08:00438504 26 07:50843004 26 10:12032104 26 10:00438504 26 09:45110304 26 08:45192904 26 08:30987604 26 07:30PIN #EVENT {month, day, time}000404 26 08:00New requesthas been stored!Retrieving a Wake-up RequestControlUnitRequest MemoryUnitrequest_pendingdone_pendingrequestrequest_PINTime Unitcurrent_time{month, day,time}At the start of a minute,retrieve any requests matching the current timeSend their PIN # to the Control UnitRetrieving a Wake-up Request438504 26 07:50843004 26 10:12032104 26 10:00438504 26 09:45110304 26 08:45192904 26 08:30987604 26 07:30PIN #EVENT {month, day, time}Current time: 07:30The current timematches the first listingRetrieving a Wake-up Request438504 26 07:50843004 26 10:12032104 26 10:00438504 26 09:45110304 26 08:45192904 26 08:30PIN #EVENT {month, day, time}9876Current time: 07:30First listing is deleted;PIN of first listing is sentto main control unitTo control unitRetrieving a Wake-up Request438504 26 07:50843004 26 10:12032104 26 10:00438504 26 09:45110304 26 08:45192904 26 08:30PIN #EVENT {month, day, time}9876Current time: 07:30First listing is deleted;PIN of first listing is sentto main control unitTo control unitCanceling Requests for a Given PIN #ControlUnitRequest MemoryUnitcancelcancel_ackPIN #Canceling Requests for a Given PIN #438504 26 07:50843004 26 10:12032104 26 10:00438504 26 09:45110304 26 08:45192904 26 08:30987604 26 07:30PIN #EVENT {month, day, time}4385Cancel all requests for PIN # 4385Canceling Requests for a Given PIN #843004 26 10:12032104 26 10:00110304 26 08:45192904 26 08:30987604 26 07:30PIN #EVENT {month, day, time}4385Done!Control Unit/Major FSMControl Unit/Major FSMControl Unit/Major FSMThank You Any
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