johnl@pico.OZ (John Leiseboer) (05/16/91)
Has anyone seen or heard of this problem before? I am using a National Semiconductor DP8390CN in 16-bit, 80x86 mode. Occasionally (actually quite often) when frames of an odd length are received by the 8390 it "loses" them. This occurs most often when the frame size is 256*n-3, or 256*n-1; where n is an integer. The 8390 may be receiving only, or have been issued with transmit commands as well, when the loss occurs. The data rate can be quite low - only 10s of frames per second. When using a generator to send frames to the 8390, with all frames identical in content and size, apparently some of the frames are dropped at random. None of the 8390's registers indicate errors on the LAN (such as FAE or CRC). The receive status is normal for subsequent identical frames. The pointers in the receive buffer ring are not corrupt - it's as if the frame was not seen at all by the 8390. Any clues would be appreciated. John Leiseboer QPSX Communications Ltd Perth, Westerm Australia Phone: +61 9 324 1641 FAX: +61 9 324 1642 email: j.leiseboer@qpsx.oz.au