LAN9217 Datasheet, PDF (122/134 Pages) SMSC Corporation – 16-bit High-Performance Single-Chip 10/100 Ethernet Controller with HP Auto-MDIX

6.3
16-bit High-Performance Single-Chip 10/100 Ethernet Controller with HP Auto-MDIX
Datasheet
PIO Burst Reads
In this mode, performance is improved by allowing up to 16 WORD read cycles back-to-back. PIO
Burst Reads can be performed using Chip Select (nCS) or Read Enable (nRD). Either or both of these
control signals must go high between bursts for the period specified.
A[7:5]
A[4:1]
nCS, nRD
Data Bus
Figure 6.2 PIO Burst Read Cycle Timing
Note: The “Data Bus” width is 16 bits
Table 6.4 PIO Burst Read Timing
SYMBOL DESCRIPTION
MIN
t_csh
nCS, nRD Deassertion Time
13
t_csdv
nCS, nRD Valid to Data Valid
t_acyc
Address Cycle Time
45
t_asu
Address Setup to nCS, nRD valid
0
t_adv
Address Stable to Data Valid
t_ah
Address Hold Time
0
t_don
Data Buffer Turn On Time
0
t_doff
Data Buffer Turn Off Time
t_doh
Data Output Hold Time
0
TYP
MAX UNITS
ns
30
ns
ns
40
ns
ns
7
ns
ns
Note: A PIO Burst Read cycle begins when both nCS and nRD are asserted. The cycle ends when
either or both nCS and nRD are deasserted. They may be asserted and deasserted in any
order.
Revision 1.5 (07-18-06)
122
DATASHEET
SMSC LAN9217