Start Up ! - Implementing
8-line-to-3 line Priority Encoder
IC: 74LS148
Prosperties
- Active-Low 8x inputs & Active Low 3x outputs(output component code of binary)
- 1x Enable input (Active-low)
- 1x Enable output (Low while EI “0” and all ins “1”)
- 1x GS extra input
- Higher num Priority
Extentions
- integrate to a 16-L-to-4-line Encoder
Decimal-to-BCD Priority Encoder
IC: 74HC147
Prosperities
- 10x Active-Low inputs
- 4x Active-Low outputs
- Output 4x ‘1’ when all inputs all Nonactive
Multiplexers(MUX) &Data Distributors(DEMUX)
Function
1 Any logic functions can be specified with MUX, by add logics before in->input port 2 MUX->forms of N-1/N 3 16-inputs Multiplexers using 2x 8-inputs
MUX
4-input Multiplexer
- 2x Data select ports : S0 S1. called “Address”
- 4x Data inputs:D0-D3
- 1x Data output: Y
Prosperities
- 4x Send ports
- 1x Transmission line as connection (BUS)
- 4x Received Ports
- Data Selectors for Address (2-bit for 4x selections)
8-input Multiplexer
- 3x selects
- 8x inputs
- 1x output
IC: 74LS153
IC: 74LS151
Extensions
Implement almost all Logic Functions in MUX(Based on SOP format) 真值表对应作图 地址端口少一或一致 Methods:Enable inputs->active Address
IC: 74LS148
- 4-bit of 2-selectors MUX
- used in 2x (4-bit binary) selection
- Common Control Panel
* 1x Enable for all MUXs
* 1x Data selector port
Extensions
- A 7-segment Display Multiplexers
DEMUX
Can be implemented with DECODER
Parity Generators/Checks 奇偶发生/校验器
IC: 74LS280
Function as Error-Detection Can check 9-bits
Tips
MSB refers to higher num while LSB to lower num.