CS8900-CQ View Datasheet(PDF) - Cirrus Logic
Part Name
Description
MFG CO.
CS8900-CQ Datasheet PDF : 132 Pages
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CS8900
• all packets received are of legal length with
valid CRC;
• each packet follows its predecessor by less
than 52 µs; and,
• the DA of each packet passes the DA filter.
Example of StreamTransfer
Figure 5.10 shows how four back-to-back
frames, followed by five back-to-back frames,
would be received without StreamTransfer. Fig-
ure 5.11 shows how the same sequence of frames
would be received with StreamTransfer.
If any of these conditions are not met, the
CS8900 exits StreamTransfer by generating
RxOK and RxDMA interrupts. The CS8900 then
returns to either Memory, I/O, or DMA mode,
depending on configuration.
Receive DMA Summary
Table 5.11 summarize the Receive DMA con-
figuration options supported by the CS8900.
4 Back-to-Back Frames
T > 52 us
5 Back-to-Back Frames
Interrupt
Request
9 Interrupts for 9 "Good" Packets
Time
Figure 5.10. Receive Example Without StreamTransfer
4 Back-to-Back Frames
T > 52 us
5 Back-to-Back Frames
Interrupt
Request
2 Interrupts for 9 "Good" Packets
Time
Figure 5.11. Receive Example With StreamTransfer
RxDMAonly
(Register 3,
RxCFG, Bit 9)
1
1
0
0
0
AutoRxDMAiE
(Register 3,
RxCFG, Bit A)
NA
RxDMAiE
(Register B,
BufCFG, Bit 7)
0
NA
1
1
0
1
1
0
NA
RxOKiE
(Register 3,
RxCFG, Bit 8)
NA
NA
0
1
NA
CS8900 Configuration
Receive DMA used for all receive frames,
without interrupts.
Receive DMA used for all receive frames, with
BufEvent interrupts.
Auto-Switch DMA used if necessary, without
interrupts.
Auto-Switch DMA used if necessary, with
RxEvent and BufEvent interrupts possible.
Memory or I/O Mode only.
Table 5.11. Receive DMA Configuration Options
98
DS150PP2
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