# what does it mean 4 bit counter, 4 bit memory

Discussion in 'General Electronics Chat' started by vead, Dec 29, 2013.

Nov 24, 2011
621
8
I am little bit confused here
what does it mean 4 bit counter how many event it may be count
4 bit ram how many bit it may be store

2. ### ScottWang Moderator

Aug 23, 2012
4,925
777
4 bits counter that it will count as below:

4 bits counter
Code ( (Unknown Language)):
1.
2. Num b3 b2 b1 b0
3. ----------------------
4.   0      0   0   0   0
5.   1      0   0   0   1
6.   2      0   0   1   0
7.   3      0   0   1   1
8.   4      0   1   0   0
9.   5      0   1   0   1
10.   6      0   1   1   0
11.   7      0   1   1   1
12.   8      1   0   0   0
13.   9      1   0   0   1
14.   a      1   0   1   0
15.   b      1   0   1   1
16.   c      1   1   0   0
17.   d      1   1   0   1
18.   e      1   1   1   0
19.   f       1   1   1   1
20.
4 bit ram as 74LS89 - 64-Bits Random Access Memory(Open Collector).
It has 4 bits x 16 = 64 bits memory cell to store the 4 bits and 16 words of datas.

Last edited: Dec 29, 2013

Nov 24, 2011
621
8
4 bit counter 2*2*2*2=16 possible combinations it can count 16 events
4 bit ram what does it mean 4X16

4. ### ScottWang Moderator

Aug 23, 2012
4,925
777
The digital number counting with parallel as:
1 pin - 1 bit
4 pins - 4 bits
8 pins - 8 bits = = 1 byte
4 bits = 1 nibble
4 bits = 1/2 byte(half byte)
2 bytes = 1 word
so 4 bits = 1/2 byte = 1 bibble

The meaning of 4 x 16 is discribe the memory has 4 bits and 16 positions to store, so 4 bits x 16 = 64 bits.

Last edited: Dec 29, 2013
5. ### shteii01 AAC Fanatic!

Feb 19, 2010
3,500
511
In this specific case it means that you have a table. The table has 16 rows, 4 columns. The 4 columns represent the 4 bits. Each cell of the table can hold one bit. A whole row will hold 4 bits.

Nov 24, 2011
621
8

what is memory location i think 64 is memory location to store 4 bit data

7. ### ScottWang Moderator

Aug 23, 2012
4,925
777
Go to check the internal structure of 74LS89 carefully on page 2 of #2.

There are 4 positions for 4 bits, 64 positions for 64 bits.

That is just like the LED dot matrix, whatever you like to say as 4 rows and 16 columns or 4 columns and 16 rows.