SMSC LAN91C111 - Manual (Page 103)

10/100 Non-PCI Ethernet Single Chip MAC + PHY
Datasheet
SMSC LAN91C111 REV C 103 Revision 1.91 (08-18-08)
DATASHEET
Latched W-R
combined with
nCMD nRD I/O Read strobe - asynchronous read accesses. Address is valid
before its leading edge. Must not be active during DMA bursts if
DMA is supported.
Latched W-R
combined with
nCMD nWR I/O Write strobe - asynchronous write access. Address is valid
before leading edge . Data latched on trailing edge. Must not be
active during DMA bursts if DMA is supported.
nSTART nADS Address strobe is connected to EISA nSTART.
RESDRV RESET
nBE0 nBE1 nBE2
nBE3 nBE0 n BE1 nBE2
nBE3 Byte enables. Latched on nADS rising edge.
IRQn INTR0 Interrupts used as active high edge triggered
D0-D31 D0-D31 32 bit data bus. The bus byte(s) used to access the device are a
function of nBE0-nBE3:
Not used = tri-state on reads, ignored on writes. Note that nBE2 and
nBE3 override the value of A1, which is tied low in this application.
Other combinations of nBE are not supported by the LAN91C111.
Software drivers are not anticipated to generate them.
nEX32
nNOWS
(optional additional
logic) nLDEV nLDEV is a totem pole output. nLDEV is active on valid decodes of
LAN91C111 pins A15-A4, and AEN=0. nNOWS is similar to nLDEV
except that it should go inactive on nSTART rising. nNOWS can be
used to request compressed cycles (1.5 BCLK long, nRD/nWR will
be 1/2 BCLK wide).
THE FOLLOWING SIGNALS SUPPORT SLAVE DMA TYPE "C" BURST CYCLES
BCLK LCLK EISA Bus Clock. Data transfer clock for DMA bursts.
nDAK<n> nDATACS DMA Acknowledge. Active during Slave DMA cycles. Used by the
LAN91C111 as nDATACS direct access to data path.
nIORC W/nR Indicates the direction and timing of the DMA cycles. High during
LAN91C111 writes, low during LAN91C111 reads.
nIOWC nCYCLE Indicates slave DMA writes.
nEXRDY nRDYRTN EISA bus signal indicating whether a slave DMA cycle will take place
on the next BCLK rising edge, or should be postponed. nRDYRTN
is used as an input in the slave DMA mode to bring in EXRDY.
UNUSED PINS
VCC nVLBUS
Table 12.3 EISA 32 Bit Slave Signal Connections (continued)
EISA BUS
SIGNAL LAN91C111
SIGNAL
NOTES
nBE0 nBE1 nBE2 nBE3
0 0 0 0 Double word access
0 0 1 1 Low word access
1 1 0 0 High word access
0 1 1 1 Byte 0 access
1 0 1 1 Byte 1 access
1 1 0 1 Byte 2 access
1 1 1 0 Byte 3 access