|
Hi Chiyuan, Thanks for the reply.But this speed is not enough to build our application. Since we intend to build a conferencing server(RTP mixer) and use the DSP Starter kit to do the mixing part and the host, to take care of receiving input data and sending the mixed data to the network, AND the INPUT data and the MIXED data needs to be transferred TO and FRO btw the host-pc and the TARGET DSP within 20 msec(which is RTP packetization time) and every 20msec.The RTP data size is 160bytes. For this we intended to use RTDX through the USB JTAG interface,but this is taking too much time now. Please give your suggestions on any other way of doing this using the DSP Starter Kit... Thanks, Prakash. At 10:32 AM 1/21/03 -0800, Chiyuan wrote: >Hi, > I just came across to the topic of RTDX recently. I make some comments >bassed on my personal experience. Hope it help, > > 1. TI only support RTDX over JTAG inerface. If you really need high >bandwidth, you might want to consider High Speed RTDX . > 2. I belive it takes more time to do H2T transfer than T2H. > 3. My experience shows that it takes about 14 ms to transfer a message with >only one 16 bit integer (plus some overhead) from Target-2-Host. If the >message has 20 integers, the transfer time is increase to 29.5 ms. > 4. The following codes take about 288 cycles, > RTDX_write( one integer) > RTDX_Poll > The following codes take 326 cycles > RTDX_write( 20 integer) > RTDX_Poll > The call to RTDX_Poll takes 51 cycles. > All these number should be deterministic. But I belive the data >transfering job is really done by a background thread. The time for this >background process to transfer the data to Host is NOT deterministic. Many >factors affect the transfering time. > >Chiyuan Chiang >System Engr. >BAE Systems/CPI > -----Original Message----- > From: Ulrich Prakash [mailto:] > Sent: Tuesday, January 21, 2003 5:11 AM > To: > Subject: [c54x] C5416 - Doubt on RTDX library's SPEED. > Hi, > > I have a doubt regarding the SPEED of the RTDX library. > I am using the TMS320VC5416DSK(C5416 DSP Starter Kit)... > > I am sending 160bytes of data from the HOST to the TARGET and immediately >from the TARGET back to the HOST using the RTDX library. > > The time taken for this operation (i.e. starting from the time when the >host sends the data, to the time when the host receives back the data) is >230 msec.... > > I am not able to understand why it takes SO MUCH TIME,since the period of >1 clock cycle of the DSP is 40nanosec?Also the minimum speed of the USB >itself is around > 1.5MegaBytes/sec and is very much higher compared to 230msec period. ... > > And this operation of time(160msec) taking up around 4,00,00,000 clk > cycles(4 crore cycles) which is TOO MANY clock cyles. > > Any clues about why this is taking so much time? > (Also attaching the test files for reference). > > Also any rough idea about how many cycles does RTDX_Poll call take?and how >many cyles do RTDX_Read call and RTDX_ReadNB take? > > Any information related to this might be very useful. > > Thanks, > > ************************************************** > M. ULRICH PRAKASH > Networking Technologies Lab, > HCL Technologies Ltd., > 184 N S K Salai, > Vadapalani, Chennai 600 026 > Tel: 91 - 44 - 372 8366 x1136 Fax: 480 6640 > Visit:: http://voip.hcltech.com > ********************************************************* > > _____________________________________ > Note: If you do a simple "reply" with your email client, only the author >of this message will receive your answer. You need to do a "reply all" if >you want your answer to be distributed to the entire group. > > _____________________________________ > About this discussion group: > > To Join: Send an email to > > To Post: Send an email to > > To Leave: Send an email to > > Archives: http://www.yahoogroups.com/group/c54x > > Other Groups: http://www.dsprelated.com > ">http://docs.yahoo.com/info/terms/ |