LAN91C100FD_08 Datasheet, PDF (35/77 Pages) SMSC Corporation – FEAST Fast Ethernet Controller with Full Duplex Capability

FEAST Fast Ethernet Controller with Full Duplex Capability
OFFSET
C
NAME
INTERRUPT ACKNOWLEDGE
REGISTER
RX_DISC
INT
Reserved
RX_OVRN
INT
TYPE
WRITE ONLY
SYMBOL
ACK
TX EMPTY
INT
TX INT
OFFSET
D
NAME
INTERRUPT MASK REGISTER
TYPE
READ/WRITE
SYMBOL
MSK
RX_DISC
INT
0
Reserved
0
EPH INT
0
RX_OVRN
INT
0
ALLOC
INT
0
TX EMPTY
INT
0
This register can be read and written as a word or as two individual bytes.
TX INT
0
RCV INT
0
The Interrupt Mask Register bits enable the appropriate bits when high and disable them when low. A
MASK bit being set will cause a hardware interrupt.
Note: The Bit 7 mask must never be written high (1).
RX_DISC INT - Set when the nRXDISC PIN COUNTER in the RCV register increments to a value of FF.
The RX_DISC INT bit latches the condition for the purpose of being polled or generating an interrupt, and
will only be cleared by writing the acknowledge register with the RX_DISC INT bit set.
Reserved – Must be 0.
EPH INT - Set when the Ethernet Protocol Handler section indicates one out of various possible special
conditions. This bit merges exception type of interrupt sources, whose service time is not critical to the
execution speed of the low level drivers. The exact nature of the interrupt can be obtained from the EPH
Status Register (EPHSR), and enabling of these sources can be done via the Control Register. The
possible sources are:
1. LINK - Link Test transition
2. CTR_ROL - Statistics counter roll over
3. TXENA cleared - A fatal transmit error occurred forcing TXENA to be cleared. TX_SUC will be low
and the specific reason will be reflected by the bits:
3.1 SQET - SQE Error
3.2 LOST CARR - Lost Carrier
3.3 LATCOL - Late Collision
3.4 16COL - 16 collisions
Any of the above interrupt sources can be masked by the appropriate ENABLE bits in the Control Register.
1) LE ENABLE (Link Error Enable), 2) CR ENABLE (Counter Roll Over), 3) TE ENABLE (Transmit Error
Enable)
EPH INT will only be cleared by the following methods:
1. Clearing the LE ENABLE bit in the Control Register if an EPH interrupt is caused by a LINK_OK
transition.
2. Reading the Counter Register if an EPH interrupt is caused by statistics counter roll over.
SMSC LAN91C100FD Rev. D
Page 35
DATASHEET
Revision 1.0 (09-22-08)