High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
Datasheet
SMSC LAN9312
449
Revision 1.4 (08-19-08)
DATASHEET
15.5.7
RX Data FIFO Direct PIO Burst Read Cycle Timing
Please refer to
Section 8.4.7, "RX Data FIFO Direct PIO Burst Reads," on page 109
for a functional
description of this mode.
Note:
A RX Data FIFO direct PIO burst read cycle begins when both nCS and nRD are asserted.
The cycle ends when either or both nCS and nRD are de-asserted. They may be asserted and
de-asserted in any order.
Note:
Fresh data is supplied each time A[2] toggles.
Figure 15.7 RX Data FIFO Direct PIO Burst Read Cycle Timing
Table 15.11 RX Data FIFO Direct PIO Burst Read Cycle Timing Values
SYMBOL
DESCRIPTION
MIN
TYP
MAX
UNITS
t
csh
nCS, nRD De-assertion Time
13
nS
t
csdv
nCS, nRD Valid to Data Valid
30
nS
t
acyc
Address Cycle Time
45
nS
t
asu
Address, FIFO_SEL Setup to nCS, nRD Valid
0
nS
t
adv
Address Stable to Data Valid
40
nS
t
ah
Address, FIFO_SEL Hold Time
0
nS
t
don
Data Buffer Turn On Time
0
nS
t
doff
Data Buffer Turn Off Time
9
nS
t
doh
Data Output Hold Time
0
nS
A[2]
nCS, nRD
D[31:0]
END_SEL
FIFO_SEL
t
asu
t
acyc
t
adv
t
csdv
t
don
t
acyc
t
acyc
t
csh
t
adv
t
adv
t
ah
t
doh
t
doff