CS8900-CQ3 Cirrus Logic, CS8900-CQ3 Datasheet - Page 98

• Manufacturer Part Number: CS8900-CQ3
• Description: Crystal LAN ISA Ethernet Controller
• Manufacturer: Cirrus Logic

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If any of these conditions are not met, the CS8900A
exits StreamTransfer by generating RxOK and
RxDMA interrupts. The CS8900A then returns to
either Memory, I/O, or DMA mode, depending on
configuration.
Interrupt
Request
RxCFG,Bit 9)
98
RxDMAonly
(Register 3,
Interrupt
Request
all packets received are of legal length with val-
id CRC;
each packet follows its predecessor by less than
52 ms; and,
the DA of each packet passes the DA filter.
1
1
0
0
0
AutoRxDMAiE
RxCFG, Bit A)
4 Back-to-Back Frames
(Register 3,
4 Back-to-Back Frames
NA
NA
1
1
0
BufCFG, Bit 7)
(Register B,
Figure 28. Receive Example Without Stream Transfer
RxDMAiE
Figure 29. Receive DMA Configuration Options
Table 29. Receive DMA Configuration Options
CIRRUS LOGIC PRODUCT DATA SHEET
NA
0
1
0
1
2 Interrupts for 9 "Good" Packets
9 Interrupts for 9 "Good" Packets
RxCFG, Bit 8)
T > 52 us
(Register 3,
T > 52 us
RxOKiE
NA
NA
NA
0
1
5.6.5 Example of StreamTransfer
Figure 28 shows how four back-to-back frames,
followed by five back-to-back frames, would be re-
ceived without StreamTransfer. Figure 29 shows
how the same sequence of frames would be re-
ceived with StreamTransfer.
5.6.6 Receive DMA Summary
Table 29 summarize the Receive DMA configura-
tion options supported by the CS8900A.
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 inter-
rupts.
Auto-Switch DMA used if necessary, with RxEvent
and BufEvent interrupts possible.
Memory or I/O Mode only.
Crystal LAN™ ISA Ethernet Controller
5 Back-to-Back Frames
CS8900A Configuration
5 Back-to-Back Frames
Time
Time
CS8900A
DS271PP3