KS8995MA Evaluation Board User’s Guide
Micrel Inc. Confidential
Page 25
11/3/2006
And we will send 64 byte packets from the Smartbits tester to port 2 destined for port 1 at
100 Mbps. We will see that the packet rate the Smartbits tester receives from port 2 will be
about 50 Mbps, and the packet rate the Smartbits tester receives from port 1 will be about 25
Mbps.
PSPI Procedure:
1. Connect the Smartbits tester to the KS8995MA with standard CAT-5 cables.
Connect port 1 from the Smartbits to port 1 on the KS8995MA and port 2 on the
Smartbits tester to port 2 on the KS8995MA, etc…
2. Connect your computer to the KS8995MA evaluation board with a parallel port
cable.
3. Configure the jumper settings on the board for SPI mode. See section 4.3 for details.
Power on the board, or press the manual reset if continuing from a previous test.
4. Open an MSDOS prompt and navigate to the directory where you have pspi.exe
stored. Make sure that the “rtlimit.txt” file is in the same directory.
5. At the MSDOS command prompt type “pspi rtlimit.txt”. This invokes the rate
limiting script which programs the low priority transmit and receive rate limits for
port 2 and enables the rate limiting feature. Please see the rtlimit.txt script for more
details and the eMAct register settings.
6. Configure the Smartbits tester with the rtlimit.prf configuration file.
7. Open the Smartbits counter display to show rates for port 1 and port 2.
8. Transmit packets from all ports so that the KS8995MA can learn addresses.
9. Stop all transmission and clear the Smartbits counters.
10. Transmit packets continuously from port 1 to port 2 at line rate. You should see
packets transmitted from port 2 back to the Smarbits tester at about 99,971 packets/s.
99,971 packets/s * 64 bytes/packet*8 bits/byte
≈
51.1 Mbps
We programmed in 0x61A = 1562.
1562 units * 32,768 bits/s per unit
≈
51.1 Mbps
11. Transmit packets continuously from port 2 to port 1 at line rate. You should see
packets transmitted to port 2 at about 49,864 packets/s.
49,864 packets/s*64 bytes/packet*8bits/byte
≈
25.5 Mbps
We programmed in 0x30D = 781
781 units *32,768 bits/s per unit
≈
25.5 Mbps
WPSPI Procedure:
1. Follow steps 1-3 above in PSPI procedure.
2. Open an MSDOS prompt and navigate to the directory where you have wpspi.exe
stored. Make sure that the “rtlimit.txt” file is in the same directory.
3. At the MSDOS command prompt type “95m rtlimit.txt”. This will configure the
Smartbits tester with the “rtlimit.txt” configuration file. The graphical interface should
be configured as shown below.
