ATNGW100 Atmel, ATNGW100 Datasheet - Page 4

• Manufacturer Part Number: ATNGW100
• Description: KIT AVR32 NETWORK GATEWAY
• Manufacturer: Atmel
• Series: AVR®32r
• Type: MCUr

Specifications of ATNGW100

• Contents: Board and Linux Dev. and Debug Toolchain
• Processor To Be Evaluated: AT32AP7000
• Data Bus Width: 32 bit
• Interface Type: RS-232, Ethernet, USB
• Silicon Manufacturer: Atmel
• Core Architecture: AVR
• Core Sub-architecture: AVR UC3
• Silicon Core Number: AT32AP7000
• Silicon Family Name: AVR
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• For Use With/related Products: AT32AP7000, AT32AP7001, AT32AP7002
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4 Results
Table 3-1. Iperf measurement results
5 Further improvements
6 References
Board
ATSTK1000
ATNGW100
4
AVR32705
Kernel
2.6.23-rc7
2.6.23-rc6
+ RX offset
+ noncoherent RX
+ avoid RX copy
+ RX offset
+ noncoherent RX
+ avoid RX copy
put_page
on and it is no longer used as a DMA buffer, the reference count drops to zero and
the page is freed.
The iperf measurement results are shown in Table 3-1. The measurements were
obtained as follows.
•
•
•
•
In the end, the three optimizations combined result in a 21% bandwidth increase on
the STK1000 and a 16.3% bandwidth increase on the NGW100.
Some of the results were a bit surprising. Since the NGW100 has lower memory
bandwidth than the STK1000 (16- vs 32-bit SDRAM databus), it is very strange that it
apparently had less benefit from avoiding the copy operation. Also, the TCP TX
bandwidth became lower on both the STK
RX copy” patch was applied.
Unless this is pure noise, it seems to indicate that the new driver handles certain
corner cases less than optimally, and there might be more room for improvement in
the driver.
Information about AT32AP7 is available on
1. Iperf website:
2. How SKBs work:
TCP RX bandwidth: “iperf –s” on the target and “iperf –c 192.168.1.231” on the
host.
TCP TX bandwidth: “iperf –s” on the host and “iperf –c 192.168.1.21” on the
target.
UDP RX datagram loss: “iperf –s –u” on the target and “iperf –c 192.168.1.231 –u
–b 60000000” on the host.
UDP TX datagram loss: “iperf –s –u” on the host and “iperf –c 192.168.1.21 –u –b
60000000” on the target.
(). Eventually, when a page has been freed from all the fragment lists it was
54.6
54.5
58.8
66.1
43.6
43.6
47.6
50.7
RX
TCP Bandwidth (Mbit/s)
http://dast.nlanr.net/Projects/Iperf/
http://vger.kernel.org/~davem/skb.html
69.1
71.3
70.3
65.5
56.3
55.3
55.7
50.9
TX
®
http://www.atmel.com/avr32/
1000 and the NGW100 when the “avoid
UDP Datagram Loss @ 60 Mbps
0.039%
14%
17%
44%
50%
46%
19%
0%
RX
32066A-AVR32-02/08
0%
0%
0%
0%
0%
0%
0%
0%
TX