90 3-bit 4-position register

90 : 3-bit 4-position register

How it works

Decodes addresses and stores the bits using multiplexers.

How to test

To write set the 3 data bits (WriteData0-WriteData2), address of the register to be written to (WriteAddress0/WriteAddress1) and toggle WriteEnable to write the 3-bits to the register at address. To read data set the address of the register to read (ReadAddress0/ReadAddress1) and the data is output on Data0-Data2. The internal state for Data2 at all addresses and an inverted WriteEnable is also output.


# Input Output
0 WriteData0 OutData0
1 WriteData1 Data2Address0
2 WriteData2 Data2Address1
3 WriteAddress0 OutData2
4 Writeaddress0 Data2Address2
5 WriteEnable Data2Address3
6 ReadAddress0 OutData1
7 ReadAddress1 NotWriteEnable