topic USB time in 8-bit Microcontrollers

USB time

CCandido — Sat, 26 Feb 2011 21:53:02 GMT

Helo,

for(i=0;i<10;i++) // send 10 frame

                 {

                        EP2_Buffer[0] =3;
                        EP2_Buffer[1] = i;
                        EP2_Buffer[2] =0xAA;

                    EndPoint_IN(EP2,64);     <----------- error not send 10 frame

while( wait send frame....how do ?) <-------- what BIT ( CheckEndPoint___IN )

                      PTBD^=0x30;                       <----- test see error
                }

solution....

EndPoint_IN(EP2,64);

while( wait send frame )

next frame....loop

how do CheckEndPoint___IN ( what it bit in bitmap all usb )

if not check not send all frames....

thanks,

Carlos,

Re: USB time

Tsuneo — Mon, 28 Feb 2011 00:30:55 GMT

> how do CheckEndPoint___IN ( what it bit in bitmap all usb )

Check the OWN bit of the BD (Buffer Descriptor) for the target IN endpoint.
On your code, EndPoint_IN() should set this bit to 1, when it passes the endpoint buffer to the SIE. When the SIE completes IN transaction, the OWN bit drops by the SIE.
Therefore, by polling this bit for the transition from 1 to 0, you know the completion of the transaction.

OR
- Poll TOKDNEF bit of INTSTAT. This bit raises when a transaction completes on one of endpoints.
- STAT register points the target endpoint, when a transaction finishes on this endpoint.
This method fits better for process by hardware interrupt, rather than polling.

The real code depends on the way how the stack declares BD.
Usually, stacks have a macro or a function to do this job.

What is the example, on which you are working?

Tsuneo

Re: USB time

CCandido — Mon, 28 Feb 2011 01:45:20 GMT

hi,

for(c=0;c<10;c++){ send 10 = 10 not failure

                       EP2_Buffer[0] =3;
                       EP2_Buffer[1] =c;
                       EP2_Buffer[2] =0xAA;

while( CheckEndPointIN2( )); checking = ok ,now runinng

                       EndPoint_IN(EP2,64);
                             PTBD^=0x30;
                                                                    NOTE time interval = 15ms ( descriptor = 0 interval )

                       }

//----------------------------------------------------------------------------------------

UINT8 CheckEndPointIN2( void )
{

if(! EP2_Set.Stat.McuCtlBit.OWN)
return 0;
return 1;

}

//--------------------------------------------------------------------------------------------

packet bytes = interval 15ms

decreasing the time of 15 ms?

Tsuneo thanks,

Carlos,