I am currently unable to transmit data using the 21440 on the IXP1200 evaluation board. I hope someone can give me some insight into what I may be doing wrong. I am only having problems with transmit, my receive code appears to work fine. I have two of the 100Mbps ports connected by a Xover cable. All I am trying to do is send a minimal ethernet packet from one port to the other. Here is a minimal program that exhibits my problem (I load it into the S-ARM with the VxWorks loader). I am presenting pseudo-code for readability. I can send you real code too if that helps. // Initialize 21440 ports 6 & 7 which are connected by an X-cable // The port CSRs are at offsets 0x38406000 and 0x38407000 respectively. // PORT_CTR is at 0x14, FFO_BUS at 0x48, TX_ERR_MOD at 0x50, and // TX_TSHD_BOFF at 0x54 from the initial offsets. PORT_CTR = PTRST & CTRST PORT_CTR = CNRST FFO_BUS = BEND TX_ERR_MOD = XCLS & LCLS & UNFS TX_TSHD_BOFF = 0xAF (BLK = 84 bytes, TSD = 124 bytes) PORT_CTR = TXEN & RXEN INT_EN = STOPE & OVFCE & LNCHE & TXERE & TXOKE & RXEVE & RXOKE // Initialize the IX bus RDYBUS_TEMPLATE_PROG = 0xFFFFFFF7, 0xFFFFFFFB, 0xFFFFFFFF RDYBUS_SYNCH_COUNT_DEFAULT = 0 RCV_RDY_CTL = 0 XMIT_RDY_CTL = 0 RDYBUS_TEMPLATE_CTL = ER & TM & MS // Initialize a packet in SRAM static uint8 packet[] = { 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x00, 0x06, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06 }; I copy this into SRAM and print it out again to verify that the copy worked correctly. BTW, is SRAM little-endian? // Initialize and start a uEngine I use it to run the following uCode program. ---- Start uCode ----- #macro imm32 [destReg, const] immed_w1 [destReg, ((const >> 16) & 0xFFFF)] immed_w0 [destReg, (const & 0xFFFF)] #endm #macro imm16 [destReg, const] immed [destReg, const] #endm #macro move [destReg, srcReg] alu [destReg, --, B, srcReg] #endm #macro set_field [reg, offset, val] alu [reg, reg, OR, val, offset] #endm #define BUFFER 0x1400 ; SRAM packet buffer .xfer_order $xfer0 $xfer1 $xfer2 $xfer3 $xfer4 $xfer5 $xfer6 $xfer7 imm32 [sram_addr, BUFFER] imm16 [tfifo_addr, 0] sram [read, $xfer0, sram_addr, 0, 8], ctx_swap t_fifo_wr [$xfer0, tfifo_addr, 0, 4], ctx_swap imm16 [control, 0] set_field [control, <<0, 6] ; PID set_field [control, <<7, 0] ; ERR set_field [control, <<8, 1] ; SOP set_field [control, <<9, 1] ; EOP set_field [control, <<10, 3] ; VLD set_field [control, <<13, 2] ; QWD set_field [control, <<16, 0] ; PREP set_field [control, <<17, 0] ; TXASIS set_field [control, <<18, 0] ; TXER move [$xfer0, control] imm16 [$xfer1, 0] imm16 [tfifo_addr, 128] t_fifo_wr [$xfer0, tfifo_addr, 0, 1], ctx_swap fast_wr [0, xmit_validate] fast_wr [1, thread_done] ctx_arb [kill] ---- End uCode ----- CONCLUSION: I expected that after this code ran (after the thread_done signal), I would get an TXOK interrupt on port 6 and an RXOK interrupt on port 7. However, all that happens is that XMIT_PTR is incremented from 0 to 1 and nothing else. What am I missing/forgetting? Thanks for any help or suggestions, Tammo