topic Re: Unexpected behaviour access mini flex bus Memory mapped IO. in MQX Software Solutions

Unexpected behaviour access mini flex bus Memory mapped IO.

netra — Mon, 20 May 2013 06:22:39 GMT

I a using MCF52259 custom board where I am using memory mapped I/O. Using mini flex address bus and chip select 1, i am selecting D Latches. My mini flexbus data lines are connect to input of D latches and Output of D latches are connected to LEDs.

When i run my application continuously , I am not getting expected behavior.

When I put a break point after writing to address and step through . I am getting expected behavior.

i have introduced sleep after updating to address. it is of no use.

I have changed wait states but nothing working.

Please let me know what i have missed.

Re: Unexpected behaviour access mini flex bus Memory mapped IO.

Martin_ — Tue, 21 May 2013 06:02:24 GMT

Netra,

would be great if you can share:

1. picture of hardware schematic to show how exactly you connect the MCU with latches and LEDs

2. code snippet of the software you're using to configure the peripheral module and write data

3. would be nice to see also oscilloscope screenshot to show the external bus access, how it looks like on your hardware in case of unexpected behavior

Re: Unexpected behaviour access mini flex bus Memory mapped IO.

c0170 — Tue, 21 May 2013 07:06:48 GMT

Hello netra,

regarding your last posts here on the community, I recommend reading this document before you write new post here:

How to post in the MQX section and get an answer!

Your posts contain lack of details. I emphasized it the last time. Please share more (as Martin's pointed what you probably should have included) if you want to get a relevant answer.

One small addition, I have not seen that you update your threads, could you please update them with a status (share a solution, a workaround). Thank you!

Regards,

c0170

Re: Unexpected behaviour access mini flex bus Memory mapped IO.

drummer — Tue, 21 May 2013 15:06:45 GMT

I am using a similar scheme. I memory mapped my I/O and use a D-LATCH to set the output. I found that you must point to your I/O device as char * .

It will otherwise send two bytes to your D-LATCH.

#define A_ADDR

0x30020000

void qa_out(uchar new_output)

{

uchar * io_addr;

io_addr = (uchar *) A_ADDR;

*io_addr =(uchar) new_output;

}