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Department of Microelectronic Systems, Faculty of Electronics,
Telecommunications and Informatics, Gdansk University of Technology
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Parity generator
Task:
Design a circuit generating parity bit of 8-bit word.
The 8-bit word has to be set using switches SW0-SW7
on the prototype board.
Parity has to be shown on LED display:
E - even number of "ones" in 8-bit input word,
O - odd number of "ones" in 8-bit input word.
Students have to perform functional simulation and to practically
check the circuit by programming the prototype board.
The prototype board contains four seven-segment LED displays with common anode,
designed to drive segments using multiplexing.
The result should be displayed on digit AN3.
All the segments of all 4 LED displays are connected together, i.e.
all segments A are connected together, all segments B are
connected together, etc. Common anodes are for activating specific digit.
Segments (A-G) are driven with active low signal, also digits
AN0-AN3 are active low.
For example, to blank digits 0-2, signals AN0-AN2
should be driven with logic '1'.
Additionally, to display letter "A" on display 3, the following signals
have to be asserted: AN3='0' and A='0',
B='0', C='0', D='1',
E='0', F='0', G='0',
DP='1'.
UCF file for the exercise, Digilent Spartan-3 board, Spartan-3 3S200 FT256-4:
#########################################################################################
# Seven-segment LED display:
NET "led7_an_o<3>" LOC = "E13" ; # leftmost digit, active low
NET "led7_an_o<2>" LOC = "F14" ; # active low
NET "led7_an_o<1>" LOC = "G14" ; # active low
NET "led7_an_o<0>" LOC = "d14" ; # rightmost digit, active low
#
NET "led7_seg_o<7>" LOC = "E14" ; # segment 'A', active low
NET "led7_seg_o<6>" LOC = "G13" ; # segment 'B', active low
NET "led7_seg_o<5>" LOC = "N15" ; # segment 'C', active low
NET "led7_seg_o<4>" LOC = "P15" ; # segment 'D', active low
NET "led7_seg_o<3>" LOC = "R16" ; # segment 'E', active low
NET "led7_seg_o<2>" LOC = "F13" ; # segment 'F', active low
NET "led7_seg_o<1>" LOC = "N16" ; # segment 'G', active low
NET "led7_seg_o<0>" LOC = "P16" ; # segment 'dp', active low
#########################################################################################
#########################################################################################
# Slide switches:
# sw7 Sw6 sw5 sw4 sw3 sw2 sw1 sw0
NET "sw_i<0>" LOC = "F12" ; # active high when in UP position
NET "sw_i<1>" LOC = "G12" ; # active high when in UP position
NET "sw_i<2>" LOC = "H14" ; # active high when in UP position
NET "sw_i<3>" LOC = "H13" ; # active high when in UP position
NET "sw_i<4>" LOC = "J14" ; # active high when in UP position
NET "sw_i<5>" LOC = "J13" ; # active high when in UP position
NET "sw_i<6>" LOC = "K14" ; # active high when in UP position
NET "sw_i<7>" LOC = "K13" ; # active high when in UP position
#########################################################################################
Fig. Connections of segments and digits of LED display. Example of displaying digit '2'
