Programming instructions

74xx
 National Instruments Corporation 6-47 Multisim Component Reference Guide
6.4.81 74xx249 (BCD-to-seven segment dec)
The BCD -to-seven-segment decoder/driver features active-high outputs for driving lamp
buffers. It has full ripple-blanking input/output controls and a lamp test input.
BCD-to-seven-segment decoder/driver truth table:
DECIMAL
OR
FUNCTION
INPUTS
BI/RBO
OUTPUTS NOTE
LTRBIDCBA abcdef g
0 1100001 11111101
1
1
1 1X00011 0110000
2 1X00101 1101101
3 1X00111 1111001
4 1X01001 0110011
5 1X01011 1011011
6 1X01101 1011111
7 1X01111 1110000
8 1X10001 1111111
9 1X10011 1111011
10 1X10101 0001101
11 1X10111 0011001
12 1X11001 0100011
13 1X11011 1001011
14 1X11101 0001111
15 1X11111 0000000
BI XXXXXX0 00000002
RBI 1000000 00000003
LT 0XXXXX1 11111114
ComponentRef.book Page 47 Thursday, December 7, 2006 10:12 AM