Design and Realization of a Prototype Hardware Platform for ...

The MegaWatch Wireless PlatformMaster's Thesis - Emanuel Corthay8 The SoftwareThe Radio Circuit Controller Finite State Machine:Manages the state of the external radio circuit. In particular, it ensures that the signals sent to thecircuit to switch its state between idle, receive and transmit mode are sent in the right sequenceaccording to the circuit specifications. It also ensures that the necessary wait times fixed by theradio circuit to switch between modes are respected. The state machine is illustrated in the figurebelow.MAC_controller state machine : RFchipModeClocked by clkcurrentstateRX = rxStartidleMode2 1mode3 = 000currentstateTX = warmUpmode3 = 100startRX0mode3 = 100line2wire_en = 1startTX0line2wire_en = 1startRX1rxBusyBuf = 0&currentstateTX = warmUpmode3 = 100setline3wire_enLow=1idle2line2wire_en = 1mode3 = 100setline3wire_enLow=1currentstateTX = doneTXTXLED = 1mode3 = 000startTX1line2wire_en = 0startRX2RX_chip_en = 1mode3 = 100line2wire_en = 0idle1mode3 = 100setline3wire_enLow=1line2wire_en = 0mode3 = 111TXchip_en =1TXLED = 1startTX2line2wire_en = 1RXmodeRX_chip_en = 1mode3 = 1001line2wire_en = 1idle0mode3 = 100line2wire_en = 1warmingupTXmode3 = 111TXchip_en = 1TXLED = 1incrementCounter = 12counter = 12000defaults:TXchip_en = 0RXchip_en = 0TXLED=0setline3wire_enLow=0warmedUp = 0incrementCounter = 0clearCounter = 0mode3 = 000RXbusyBuf = 0&RXinhibit=1 & TXinhibit = 1RXinhibit=1 & TXinhibit = 1&currentstateTX = doneTX2mode3 = 111TXchip_en = 1TXLED = 1clearCounter = 1warmedUp = 1TXmode1Figure 31 The Mode FSM of the MAC ControllerThe radio circuit mode Finite State machine is composed of the following states:• idleMode state; The radio circuit is in idle mode, consuming a minimum amount of power• RxMode state; The radio circuit is in receive mode, sending the received bit stream andclock to the decoder and the pattern signal when a frame starting sequence is detected.53 / 83