91C94 Datasheet, PDF (73/120 Pages) SMSC Corporation – ISA/PCMCIA SINGLE CHIP ETHERNET CONTROLLER WITH RAM

D RIVER SEND
Ch oo se Bank Select
R egist er 2
Call ALLOCATE
ALLOCATE
I ssue "Alloca te Memory "
Comman dt o MMU
R ead Int er rupt Status R egister
Exit Driver Send
Yes
Read Allocat ion Result
R egister
Write Allocated Packet int o
Packet # Register
Wr ite Address Pointer
R egister
Copy Part of TX Data Packet
into RAM
Allocation
No
Pass ed ?
Store Data Buf fer Pointer
Clear "Ready for Packet" Flag
Enable Allocat ion Interrupt
Write Sourc e Add re ss int o
Proper Location
C opy RemainingTX Dat a
Packet int oR AM
Enqu eue Pack et
Set "Ready for Packet" Flag
R et urn Buff ers to U pper Layer
Ret urn
FIGURE 16 – DRIVER SEND AND ALLOCATE ROUTINES
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