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RE: [Discuss-gnuradio] FPGA / new rx_buffer_inband
From: |
Eric Schneider |
Subject: |
RE: [Discuss-gnuradio] FPGA / new rx_buffer_inband |
Date: |
Sun, 7 Sep 2008 14:47:36 -0600 |
> -----Original Message-----
> From: Brian Padalino [mailto:address@hidden
> Sent: Sunday, September 07, 2008 7:21 AM
>
> Were these results for the 2 channel mode?
>
> What is the size difference within the USRP when using 2 channels? Is
> it significant or pretty insignificant?
They were from the 1 channel build.
Here is a snippet from inband_2rxhb_2tx.rbf:
ch: 0 s: 965745 delta: 8064
ch: 1 s: 965745 delta: 8064
ch: 0 s: 973809 delta: 8064
ch: 1 s: 973809 delta: 8064
ch: 0 s: 981873 delta: 8064
ch: 1 s: 981873 delta: 8064
ch: 0 s: 989937 delta: 8064
ch: 1 s: 989937 delta: 8064
ch: 0 s: 998001 delta: 8064
ch: 1 s: 998001 delta: 8064
The channels seem well aligned at least.
Unfortunately, I am getting regular segfaults on 2rx... :-/
Resource Comparison:
New 2 chan:
; Compilation Hierarchy Node ; Logic Cells ;
LC Registers ; Memory Bits ; M4Ks
; |rx_buffer_inband:rx_buffer| ; 983 (59) ;
697 ; 72576 ; 18
; |packet_builder:pb| ; 162 (162) ;
19 ; 0 ; 0
; |rx_channel_buffer:cb[0].chan_buf[0]| ; 249 (68) ;
209 ; 24192 ; 6
Orig 2 chan:
; Compilation Hierarchy Node ; Logic Cells ;
LC Registers ; Memory Bits ; M4Ks
; |rx_buffer_inband:rx_buffer| ; 546 (119) ;
318 ; 114688 ; 28
; |packet_builder:rx_pkt_builer| ; 137 (137) ;
41 ; 0 ; 0
; |fifo_1kx16:generate_channel_fifos[0].rx_chan_fifo| ; 43 (0) ;
33 ; 16384 ; 4
; |fifo_4kx16_dc:rx_usb_fifo| ; 158 (0) ;
134 ; 65536 ; 16
I haven't done any optimization yet, so I'm not sure how much the logic cell
utilization could be reduced. I imagine a fair amount of it comes from my
use of 64 bit wide data paths for header data. I may try a hybrid version
where the header data is muxed into a 16b header fifo. There shouldn't be
any performance penalty except for very short packets (< 64 bytes, e.g.
command channel). The header fifo capacity would be better utilized then as
well.
The new code has 4+2 M4Ks (vs just 4) per channel, but with no usb_fifo (+16
M4K), so memory comparison is not really apples to apples. We could split
the usb_fifo memory between the channels and give each 2-4k per channel.
--ets
- [Discuss-gnuradio] FPGA / new rx_buffer_inband, Eric Schneider, 2008/09/07
- Re: [Discuss-gnuradio] FPGA / new rx_buffer_inband, Brian Padalino, 2008/09/07
- RE: [Discuss-gnuradio] FPGA / new rx_buffer_inband,
Eric Schneider <=
- Re: [Discuss-gnuradio] FPGA / new rx_buffer_inband, Brian Padalino, 2008/09/07
- RE: [Discuss-gnuradio] FPGA / new rx_buffer_inband, Eric Schneider, 2008/09/07
- Re: [Discuss-gnuradio] FPGA / new rx_buffer_inband, Brian Padalino, 2008/09/08
- RE: [Discuss-gnuradio] FPGA / new rx_buffer_inband, Eric Schneider, 2008/09/08
- Re: [Discuss-gnuradio] FPGA / new rx_buffer_inband, Brian Padalino, 2008/09/08
- RE: [Discuss-gnuradio] FPGA / new rx_buffer_inband, Eric Schneider, 2008/09/08
- Re: [Discuss-gnuradio] FPGA / new rx_buffer_inband, Brian Padalino, 2008/09/08
- Re: [Discuss-gnuradio] FPGA / new rx_buffer_inband, George Nychis, 2008/09/08
- RE: [Discuss-gnuradio] FPGA / new rx_buffer_inband, Eric Schneider, 2008/09/08
- Re: [Discuss-gnuradio] FPGA / new rx_buffer_inband, Eric Blossom, 2008/09/08