GPIO throughput

[alimicro]

Hi

I'm just a beginner at i.MX53 and I need to gather some information about i.MX53. Im' going to select a good product of ARM cortex MCU and I think i.MX53 is the best one from view point of Freescale documentation , Good technical forum , very good Evaluation kits which is support from Freescale.

but now I don't have any evaluation kit and 2 questions are not clear for me:

I need to know how much is the maximum of GPIO throughput, I mean 3.3V GPIO

2. whether the LVDS channels can use as general purposes data transfer or they are just for LCD and graphic output?

If it's duplicated topic, sorry, just hint me where I can find the answers.

thanks in advance

[alimicro]

Hi Mark

thanks for your response.

these are useful information.

[TheAdmiral]

1. The maximum throughput on GPIO pins is a somewhat hard question to answer. The GPIO pins support PATA and CAN data streams, which can clock to ~ 66.5MHz. This is an example of what the pins can do. Note that these are already formatted data streams. If you were going to do some sort of proprietary data output in such a way that you were going to bit-bang the pin, then you would look at the datasheet, section 4.5.1 and read the slew rates for how long the pad takes to transition from low to high and high to low. You would need to decide how long the pin needed to stay at that signal level to be effectively read, and you would need to know how long it would take software to respond to the need to change the next bit in the stream. Those would be the technical considerations. I think a general rule of thumb would probably be: 66.5 MHz is probably achievable. You may be able to get up to 100 MHz, with a carefully thought out design. 400 MHz is not possible. Also note that the board capacitance attached to the pin will greatly effect the slew rates.

2. The LVDS pins on the i.MX53 are specifically used for video output. There are actually other LVDS type signals on the i.MX53 including USB and SATA. These LVDS signals are all driven by specific Phys which places the datastream into the specific format required by that function. None of these can be turned into general LVDS type signals.

Hope this helps.

[alimicro]

Hi Yuri

I know GPIO speed is depend on OS and how the code has implemented but by hardware how much clock and bit rate can obtain?

about FEC , again I know 100Mbps has supported by imx53 but for example in Linux , data stream can achieve to 100Mbps or less

because in my previous project based on S3C2440 and windows CE5 I couldn't transfer data more that 20KB per second. I know if I implement it with no OS or maybe Linux I could gain more speed(this speed is the same as serial port).

If you could do me a favour and estimate it in windows I'll appreciate you.

about S3C2440 I've just made a socket in c# as a server and just read from socket and count how many bytes received and in my PC by means of hyper-terminal I sent a big file.

in this situation maximum speed was 20KB.

here we have cortex-a8 1GHz instead of ARM9 400MHz. graphic core, GPU,VPU,DDR3 and something else which are added to i.MX53 that can we obtain much more throughput on the Ethernet based on Windows platform.

[Yuri]

I.MX53 FEC supports 100M Ethernet.

alimicro said:

Hi

I made mistake: yes this is not MCU

but I said just "ARM cortex" not cortex-m

I have another question about ethernet

in windows what is the maximum throughput in LAN connection?

I'll appreciate him if answer me.

thanks in advace

[Yuri]

GPIO performance is software implementation dependent.  

[alimicro]

Hi

I made mistake: yes this is not MCU

but I said just "ARM cortex" not cortex-m

I have another question about ethernet

in windows what is the maximum throughput in LAN connection?

I'll appreciate him if answer me.

thanks in advace

[jose]

Just a quick question, i thought imx53 is an MPU?

cortex-m are MCU series right?

and cortex-a are MPUs?