VHDL Descriptions

2. Receiver entities

Entity:  rec2.vhd
Purpose: top level receiver entity . 
Function: The input to this entity is serial data from the FM receiver. Data is stored and    
          decoded. The decoded data is displayed on LEDS and on a 7 segments display.
          A VGA monitor is used to display static data including the sensors output.  
Logic Cells Required: 763/1152

Entity: patterndetector.vhd
Purpose: Detects the pattern "552" and signals the starting of reception.
Function: This entity checks the incoming data from the FM receiver for the pattern
          "552". Once this pattern is detected, this entity sets a flag high "match".
          This flag remais high for the duration of 48 bits.
Logic Cells Required: 141/1152

Entity: buff.vhd
Purpose: Stores 48 bits.
Function: This entity accept 48 bits of serial data as long as the flag "match" is set 
          high. The output of the entity is a 48 bits word components 
used: reg.vhd (generic shift left register)
Logic Cells Required: 49/1152

Entity: er_det.vhd
Purpose: detects errors in the incoming data.
Function: This entity checks the incoming data. If the pattern"1111" is detected at a
          specified location in each  12 bits word, the word is stored in a 12 bits latch.
          Otherwise, the 12 bit latch for this word is not updated.
components used: lat.vhd (generic latch)
Logic Cells Required: 100/1152

Entity: myvhds.vhd
Purpose: displays static data on the VGA monitor.
Function: This entity checks displays static data representing sensors on the VGA monitor.
Logic Cells Required: 303/1152

Entity: multiplex.vhd
Purpose: this entity is used to test raw data.
Function: This entity checks the data before it is sent to the data decoder.
          A push button increments the content of a counter. Each counter value 
          corresponds to the contents of a latch. Data from each latch can be presented on
          the 7 segments display.
Logic Cells Required: 36/1152

Entity: button.vhd
Purpose: this entity is used to test raw data.
Function: A push button is used to increment a counter, the output of this counter is
          connected to the entity multiplex.vhd
Logic Cells Required: 18/1152

Entity: div8.vhd.vhd
Purpose: this entity divides the input clock.
Function: scales down the input clock from 25.175 Mhz to 12.3 Khz.
components used: toggle.vhd
Logic Cells Required: 11/1152

Entity: d.vhd
Purpose: D flip flop 
Function: synchronizes the input data to the receiver.
Logic Cells Required:  1/1152

Entity: toptest.vhd
Purpose: test the receiver for correct operation. The VGA driver and data decoder are not
         tested by this entity.