VHDL Descriptions

1. Transmitter entities

Entity tb_trans.vhd
Purpose:  test bench for the transmitter

Entity:  transmit.vhd
Purpose:  aggregates sensor data into a single stream for broadcast at a predefined data 
          rate
Function:  calls sensor ADC functions and sends its data to the shift register by parallel
           input.  Then, shifts data serially for output into a broadcast stream.
Logic Cells Required:  919/1152

Entity: sh_reg.vhd
Purpose: sh_reg.vhd takes in compass, vibration, temperature, and synchronization
	 data and shifts it out for transmission 
Function:  stores bits and outputs MSB & LSB with optional wrap-around.  Sh_reg can 
           take in parallel input or serial input
Logic Cells Required: 38/1152

Entity:  vibadc.vhd
Purpose:  takes in vibration ADC data and passes the data up through a buffer while
          displaying the data on LEDs
Function:  vibadc.vhd samples data from the ADC and measures the rate of which
           the highest 3 ADC bits cross a predefined threshold.  The rate determines 
           vibration sensitivity
Logic Cells Required:  500/1152

Entity:  tempadc.vhd
Purpose: takes in temperature ADC data and passes the data up through a buffer and over
         HEX 7 segment for display
Function:  program latches data at the correct interval, discards invalid bits and passes 
           data up through a buffer
Logic Cells Required:  246/1152

Entity:  compass.vhd
Purpose:  takes in compass ADC data and passes the data up through a buffer
Function:  compass.vhd latches in data from the compass ADC and displays it over LEDs
Logic Cells Required:  8/1152

Entity:  makeclks.vhd
Purpose:  creates slower clock pulses for ADC and data rate clocking
Function:  divides the global clock with a preset counter
Logic Cells Required:  180/1152