10/100 Non-PCI Ethernet Single Chip MAC + PHY
Datasheet
Chapter 5 Description of Pin Functions
PIN NO.
BUFFER
NAME
SYMBOL
DESCRIPTION
TYPE
TQFP
QFP
81-92
83-94
Address
Address
A4-A15
A1-A3
I**
Input. Decoded by LAN91C111 to
determine access to its registers.
78-80
41
80-82
43
I**
Input. Used by LAN91C111 for internal
register selection.
Address Enable AEN
I**
Input. Used as an address qualifier.
Address decoding is only enabled when
AEN is low.
94-97
96-99
nByte Enable
nBE0-
I**
Input. Used during LAN91C111 register
accesses to determine the width of the
access and the register(s) being
nBE3
accessed. nBE0-nBE3 are ignored when
nDATACS is low (burst accesses)
because 32 bit transfers are assumed.
107-104,
109-106,
Data Bus
D0-D31
I/O24**
Bidirectional. 32 bit data bus used to
access the LAN91C111’s internal
registers. Data bus has weak internal
pullups. Supports direct connection to the
system bus without external buffering.
For 16 bit systems, only D0-D15 are
used.
102-99, 76- 104-101,
73, 71-68,
66-63, 61-
58, 56-53,
51-48
78-75, 73-
70, 68-65,
63-60, 58-
55, 53-50
30
37
32
39
Reset
RESET
nADS
IS**
IS**
Input. When this pin is asserted high, the
controller performs an internal system
(MAC & PHY) reset. It programs all the
registers to their default value, the
controller will read the EEPROM device
through the EEPROM interface (Note 5.1).
This input is not considered active unless
it is active for at least 100ns to filter
narrow glitches.
nAddress
Strobe
Input. For systems that require address
latching, the rising edge of nADS
indicates the latching moment for A1-A15
and AEN. All LAN91C111 internal
functions of A1-A15, AEN are latched
except for nLDEV decoding.
35
36
40
37
38
42
nCycle
nCYCLE
W/nR
I**
Input. This active low signal is used to
control LAN91C111 EISA burst mode
synchronous bus cycles.
Write/
IS**
Input. Defines the direction of
synchronous cycles. Write cycles when
high, read cycles when low.
nRead
nVL Bus Access nVLBUS
I with
Input. When low, the LAN91C111
synchronous bus interface is configured
for VL Bus accesses. Otherwise, the
LAN91C111 is configured for EISA DMA
burst accesses. Does not affect the
asynchronous bus interface.
pullup**
SMSC LAN91C111-REV B
Revision 1.8 (07-13-05)
DATA2S3HEET
SMSC [ SMSC CORPORATION ]
