Programming instructions

74xx
 National Instruments Corporation 6-45 Multisim Component Reference Guide
6.4.80 74xx248 (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.
Notes:
1. The blanking input (BI) must be open or held at a high logic level when output
functions 0 through 15 are desired. The ripple-blanking input (RBI
) must be open or
high if blanking of a decimal zero is not desired.
2. When a low logic level is applied to the blanking input (BI), all segment outputs are off
regardless of any other input.
3. When ripple-blanking input (RBI) and inputs A, B, C, and D are at a low level with the
lamp test input high, all segment outputs go off and the ripple-blanking output (RBO)
goes to a low level (response condition).
4. When the blanking input/ripple-blanking output (BI/RBO) is open or held high and a
low is applied to the lamp-test input, all segment outputs are on.
ComponentRef.book Page 45 Thursday, December 7, 2006 10:12 AM