[SOLVED] paralle vs series at high speed

[1a2s3d4f]

Hi everyone,

Can someone explain to me the concept of serial and parallel.

For parallel
256 pcb traces needed to implement a full duplex, 10Gbps interface using two 128bit wide synchronous LVTTL buses running at 78MHz.

For Serial
The same data bandwidth can be implement using only 16 PCB trace by using 4 serial I/O, each operated at 2.5 Gbps.

Can some one please explain to me the math behind the two idea.

Thanks

 

[sreekanthr.ele]

It is not correct because f you want full duplex in serial data transfer you need to SPI protocol.
In this if you are running at 2.5gbps to transfer 128 bits you have to write a data of 16bytes for each byte it will take
1/clkspeed * 128.
So, pls check once again.

 

[AdvaRes]

For the parallel:
256 PCB traces full duplex so you have 128 Trace in each direction.
128*78=10Gbps

For the serial:
16 PCB trace in total=> 8 wire in each direction => 4 serial lines, each line consist of 2 wires for differential signaling.
4*2.5=10 Gbps

 

[1a2s3d4f]

For the parallel:
256 PCB traces full duplex so you have 128 Trace in each direction.
128*78=10Gbps

For the serial:
16 PCB trace in total=> 8 wire in each direction => 4 serial lines, each line consist of 2 wires for differential signaling.
4*2.5=10 Gbps

Hi AdvaRes,

Thank you so much for clarify the concept. I would like to make sure that I understand the concept correctly, so the 4 serial line (2 pair of differential signal) are parallel with the other 4 serial IO devices. Regarding the 2.5Gbps on each IO, and each carried 4bit. This mean each IO operated at 625MHz (clk period of 1.6ns).
Please verify with me if I understand the concept correctly.

Thanks