10/100 Non-PCI Ethernet Single Chip MAC + PHY
Datasheet
ISR
Save Bank Select & Address
Ptr Registers
Mask SMC91C111
Interrupts
Read Interrupt Register
No
Yes
RX INTR?
Yes
TX INTR?
Call TX INTR or TXEMPTY
INTR
No
Call RXINTR
Get Next TX
ALLOC INTR?
Packet
Available for
Transmission?
No
Yes
Write Allocated Pkt # into
Packet Number Reg.
Yes
No
Call ALLOCATE
Write Ad Ptr Reg. & Copy Data
& Source Address
Enqueue Packet
EPH INTR?
Yes
No
Set "Ready for Packet" Flag
Return Buffers to Upper Layer
Call EPH INTR
Disable Allocation Interrupt
Mask
MDINT?
Yes
Restore Address Pointer &
Bank Select Registers
Call MDINT
Unmask SMC91C111
Interrupts
Exit ISR
Figure 10.1 Interrupt Service Routine
SMSC LAN91C111-REV B
Revision 1.8 (07-13-05)
DATA9S9HEET
SMSC [ SMSC CORPORATION ]
