8 Replies Latest reply on Sep 13, 2011 5:21 AM by userc_44405

Read endpoint data using external logic

userc_44405 Sep 13, 2011 5:21 AM

descreption:

I fill ep2 with 512 bytes with value of 05 using "cypress usb console" and "my own VS2008 program". it successfully writes data to ep2. following trm page 9-18 external logic(avr mega8535) checks flagc(empty) when is not asserted(high) it reads data and shows on LCD. after 512 reads empty flag will be asserted.

Problem:

1- The read data are not 05 they are 65-165-218-138-201-49-174-30-173-27-146 ....(they are not random because with defferent tries results are the same)

2- because only 2 writes are successful i think this external reads will not empty the fifo

am I reading from wrong fifo OR an additional stage other than TRM page 9-18 should be done to empty fhe fifo?

regards

1. Re: Read endpoint data using external logic

prajithc_ Sep 6, 2011 7:22 AM (in response to userc_44405)

Hi,

     Can you upload your code?

Regards,

Prajith
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2. Re: Read endpoint data using external logic

userc_44405 Sep 6, 2011 10:38 PM (in response to userc_44405)
the code is for bascom:

usbGet.txt.zip 1.2 K
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3. Re: Read endpoint data using external logic

userc_44405 Sep 6, 2011 11:20 PM (in response to userc_44405)

hardware: 3684 dvk

the external logic contains a mega8535 (avr) porta of which is connected to 74ls245(data_buffer) and to fd0 to fd7

portd of avr is used for fifo control pins (sloe, slrd, fifoadr[0-1], ...) and connected to them through a 74ls245 (control_buffer), portc is connected to LCD 16*2 , portb.0 is connected to an led to blink to show the device is working.
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4. Re: Read endpoint data using external logic

userc_44405 Sep 6, 2011 11:57 PM (in response to userc_44405)

sorry it may be a hardware problem!!!!!!!!
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5. Re: Read endpoint data using external logic

userc_44405 Sep 7, 2011 11:50 PM (in response to userc_44405)
Hi

it was not hardware problem!!!

I checked it with logic analyzer all the signals are passed correctly to the 3682 board but it still gives the same data.

dscr.a51 priph.c and usbGet.bas(program for external logic) are attached.

thanks in advance.

files1.zip 5.2 K
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6. Re: Read endpoint data using external logic

userc_44405 Sep 10, 2011 10:41 PM (in response to userc_44405)

Dear Prajith

files attached is there any thing wrong?
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7. Re: Read endpoint data using external logic

prajithc_ Sep 12, 2011 7:02 AM (in response to userc_44405)
Hi,


     Are you using inverted IFCLK signal?


     Have you configured FLAGC as Empty flag?


     What is the configuration for EP6, 2x or 4x?


     Please try with the attached code. I used FLAGD for checking status (Empty) of EP2.

Regards,

Prajith

newperiph.txt.zip 2.5 K
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8. Re: Read endpoint data using external logic

userc_44405 Sep 13, 2011 5:21 AM (in response to userc_44405)

Dear Prajith


I used your code and guidance just added a OUTPKTEND=0x82 after FIFOs reset.

flagc is Working currectly as empty flag.

Now it works great. thank you very much.
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