FIFO depth

I have doubt in calculating FIFO depth.
Transmitter is writing 16 bit data with a frequency of 40 KHz.
Receiver is reading 8 bit data with a frequency of 60 KHz.
What is the depth of FIFO I need to use and how I need to calculate
the FIFO depth?

 

[naliali]

On Oct 15, 8:44 am, vishnuprasa...@gmail.com wrote:

I have doubt in calculating FIFO depth.
Transmitter is writing 16 bit data with a frequency of 40 KHz.
Receiver is reading 8 bit data with a frequency of 60 KHz.
What is the depth of FIFO I need to use and how I need to calculate
the FIFO depth?

you can consider one second or any scaled period of time(e.g. 1ms) and
calculate how many inputs your FIFO will have in this period assuming
16 bit data with 40kHz for writing rate. then calculate the depth of
your FIFO knowing the reading rate and the whole data length. the
result is like :

16 bit * 40 KHz = 640k bits/second = writing rate
8 bit * 60 KHz = 480k bits/second = reading rate

if you'd like to write in the FIFO contineusley then, you can't read
all its contents before it's overwritten! unless you have a clock
enable or handshake signal that limits your writing procedure. is it
the case? if you have only a clock enable that limits writing rate,
then its period is needed. but if you have a handshake signal you can
choose any length for your FIFO for example 1kbyte, and use a 'full-
empty' flag to set/reset a 'ready' signal for handshaking.