Altera CIC MegaCore Function - Manual (Page 29)

The multiple symbols per beat scenario applies to both the sink interface on MISO CIC filters and the
source interface of SIMO CIC filters. All other interfaces operate with a single symbol per beat, but the
interfaces also support multiple channels using packets.
Figure 3-8: Packet Data TransferFour symbols are transferred on each beat. The data transfer occurs on
cycles 1, 2, 4, and 5, when both ready and valid are asserted.
0 1 2 3
00 00 00 00
D
0
D
4
D
8
D
12
D
1
D
5
D
9
D
13
D
2
D
6 D
10
D
14
D
3
D
7
D
11
D
15
1 2 3 4 5 6 7
clk
ready
valid
startofpacket
endofpacket
channel[1:0]
data[31:24]
data[23:16]
data[15:8]
data[7:0]
error[1:0]
During cycle 1, the CIC IP core asserts
startofpacket
, and transfers the first four bytes of packet. During
cycle 5, the CIC IP core asserts
endofpacket
indicating that this is the end of the packet. The
channel
signal indicates the channel index associated with the data. For example, on cycle 1, the data D
0
, D
1
, D
2
,
and D
3
associated with channel 0 are available.
UG-CIC
2014.12.15
Packet Data Transfers 3-13
CIC IP Core Functional Description Altera Corporation
Send Feedback