Hi, I had this problem of receiving error packet from the giga port, here is how the test go. I had created some packets in the microengine, e.g. move($$dxfer0, 0xfffffff1) move($$dxfer1, 0xfffffff3) move($$dxfer2, 0xfffffff5) move($$dxfer3, 0xfffffff7) move($$dxfer4, 0xfffffff9) move($$dxfer5, 0xfffffffb) move($$dxfer6, 0xfffffffd) move($$dxfer7, 0xffffffff) sdram[write, $$dxfer0, packet_buf_addr, 0, 4], ctx_swap move($$dxfer0, 0xfffffff1) move($$dxfer1, 0xfffffff3) move($$dxfer2, 0xfffffff5) move($$dxfer3, 0xfffffff7) move($$dxfer4, 0xfffffff9) move($$dxfer5, 0xfffffffb) move($$dxfer6, 0xfffffffd) move($$dxfer7, 0xffffffff) sdram[write, $$dxfer0, packet_buf_addr, 4, 4], ctx_swap And I send out this packet to the giga port using the "L3fw8_1.uc" microcode from intel reference design. Result obtained as below: 19:21:03.445227 ff:f0:ff:ff:ff:f1 ff:ff:ff:f1:ff:ff ffff 116: fff2 ffff fff5 ffff fff4 ffff fff5 ffff fff6 ffff fff9 ffff fff8 ffff fff9 ffff fffa ffff fffd ffff fffc ffff fffd ffff fffe ffff fff1 ffff fff0 ffff fff1 ffff fff2 ffff fff5 ffff fff4 ffff fff5 ffff fff6 On the first row and the fifth row, it should be "fff3" and "fff5" respectively, but it become "fff2" and "fff4", there is one bit being modified. And also from 2nd row onward,there is some duplication occur, the 2 words "ffff fff5" has been repeated two time in row 4 and row 6. Is there anyone has this similar problem before or do you have any ideal of solving this, please send a email, thank you. Mike Wong Kim Sing R&D Engineer Institute for Communications Research 20 Science Park Road TeleTech Park #02-34/37 Singapore Science Park II Singapore 117674 Tel: 65 68729030 DID : 65 68709320 Fax: 65 67795441 Email: wongks@i2r.a-star.edu.sg Website: http://www.i2r.a-star.edu.sg