AM79C970 datasheet(163/168 Pages) AMD

163 / 168 page

AMD

1-1030

Am79C970

Figure D3 shows the event flow for the two-interrupt method:

18220A-57

Buffer

Ethernet

Controller

activity:

Software

activity:

Buffer

S0: Driver is idle.

C1: Controller is performing intermittent

bursts of DMA to fill data buffer #1.

Ethernet

Wire

activity:

N0: Packet preamble, SFD

and destination address

are arriving.

C3: SRP interrupt

is generated.

C5: Controller is performing intermittent

bursts of DMA to fill data buffer #2.

S1: Interrupt latency.

S3: Driver writes modified application

pointer to descriptor #3.

C8: Controller is performing intermittent

bursts of DMA to fill data buffer #3.

N1: 64th byte of packet

data arrives.

S4: Driver copies data from buffer #1 to the application buffer.

S5: Driver polls descriptor #2.

S7: Driver is swapped out, allowing a non-Etherenet

application to run.

S8: Driver calls application

to tell application that

packet has arrived.

S6: Driver copies data from buffer #2 to the application buffer.

C9: Controller writes descriptor #3.

C0: Lookahead to descriptor #2.

C2: Controller writes descriptor #1.

S2: Driver call to application to

get application buffer pointer.

{

S9: Application processes packet, generates TX packet.

S10: Driver sets up TX descriptor.

C4: Lookahead to descriptor #3 (

OWN).

C6: "Last chance" lookahead to

descriptor #3 (OWN).

C7: Controller writes descriptor #2.

}

}{

{

N2: EOM

C10: ERP interrupt

is generated.

}

S8A: Interrupt latency.

S7A: Driver Interrupt Service

Routine executes

RETURN.

{

Figure D3. LAPP Timeline for TWO-INTERRUPT Method

AM79C970 датащи(PDF) 163 Page - Advanced Micro Devices

AM79C970 датащи(HTML) 163 Page - Advanced Micro Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL