LAN9221 Datasheet, PDF (135/151 Pages) SMSC Corporation – High-Performance 16-bit Non-PCI 10/100 Ethernet Controller with Variable Voltage I/O

High-Performance 16-bit Non-PCI 10/100 Ethernet Controller with Variable Voltage I/O
Datasheet
6.7
PIO Writes
PIO writes are used for all LAN9221/LAN9221i write cycles. PIO writes can be performed using Chip
Select (nCS) or Write Enable (nWR). Either or both of these control signals must go high between
cycles for the period specified.
A[7:1]
nCS, nWR
Data Bus
Figure 6.6 PIO Write Cycle Timing
Note: The “Data Bus” width is 16 bits.
Table 6.7 PIO Write Cycle Timing
SYMBOL DESCRIPTION
MIN
t_cycle
Write Cycle Time
45
t_csl
nCS, nWR Assertion Time
32
t_csh
nCS, nWR Deassertion Time
13
t_asu
Address Setup to nCS, nWR Assertion
0
t_ah
Address Hold Time
0
t_dsu
Data Setup to nCS, nWR Deassertion
7
t_dh
Data Hold Time
0
TYP
MAX UNITS
ns
ns
ns
ns
ns
ns
ns
Note: A PIO Write cycle begins when both nCS and nWR are asserted. The cycle ends when either
or both nCS and nWR are deasserted. They may be asserted and deasserted in any order.
SMSC LAN9221/LAN9221i
135
DATASHEET
Revision 2.6 (12-04-08)