diff options
Diffstat (limited to 'fpga/usrp2/control_lib/newfifo/fifo_spec.txt')
| -rw-r--r-- | fpga/usrp2/control_lib/newfifo/fifo_spec.txt | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/fpga/usrp2/control_lib/newfifo/fifo_spec.txt b/fpga/usrp2/control_lib/newfifo/fifo_spec.txt new file mode 100644 index 000000000..133b9fa8e --- /dev/null +++ b/fpga/usrp2/control_lib/newfifo/fifo_spec.txt @@ -0,0 +1,36 @@ + + +FIFO and Buffer Interface Spec + +Buffer Interface Data Wires -- matches fifo36 + DATA[31:0] + FLAGS[3:0] + Bit 0 SOP + Bit 1 EOP + If SOP=1 && EOP=1, OCC contains error flags + Bits 3:2 OCC[1:0] --> 00 = all 4 bytes + 01 = 1 byte + 10 = 2 bytes + 11 = 3 bytes + +fifo36 --> {OCC[1:0],EOP,SOP,DATA[31:0]} + OCC same as buffer interface + +fifo19 --> {OCC,EOP,SOP,DATA[15:0]} + Doesn't fit well into BRAM, dist RAM ok + OCC = 1 means last word is half full + = 0 means last word is full + +fifo18 --> {EOP,SOP,DATA[15:0]} + No half-word capability? Should we drop sop instead? + +Control Wires - Data into FIFO + SRC_RDY_i Upstream has data for me + DST_RDY_o I have space + Transfer occurs if SRC_RDI_i && DST_RDY_o + +Control Wires - Data out of FIFO + SRC_RDY_o I have data for downstream + DST_RDY_i Downstream has space + Transfer occurs if SRC_RDI_o && DST_RDY_i + |