CS8900 View Datasheet(PDF) - Cirrus Logic

Part Name

Description

MFG CO.

CS8900

Highly-Integrated ISA Ethernet Controller

Cirrus Logic 

Enter Packet Transmit Process

Exit: can’t Issue command

Note: Issuing a command

at this point will cause

previous transmit frame

to be lost.

Is

TxCMD

Yes pending?

No

Host Writes Transmit Command

to the TxCMD Register

CS8900

Host Writes Transmit Frame

Length to the TxLength Register

Transmit Request

Host Reads the BusST

Register (Register 18)

Host Enters Interrupt Routine

Host Reads

ISQ

Rdy4

TxNOW

Yes

bit = 1?

No

Exit WAIT-for-interrupt

No Rdy4Tx Yes

bit = 1?

CS8900 Commits

Buffer Space to

Transmit Frame

Process other events

that caused interrupt

Host Writes

Transmit Frame

to CS8900

CS8900

Transmits Frame

Exit Transmit Process

Figure 5.13. Transmit Operation in Interrupt Mode

DS150PP2

103

Share Link: