M1AFS250-FGG256I Actel Corporation, M1AFS250-FGG256I Datasheet - Page 228

• Manufacturer Part Number: M1AFS250-FGG256I
• Description: Actel Fusion Family Of Mixed Signal Fpgas
• Manufacturer: Actel Corporation

Device Architecture
Table 2-166 • AC Waveforms, Measuring Points, and Capacitive Loads
Table 2-167 • LVDS
Figure 2-133 • BLVDS/M-LVDS Multipoint Application Using LVDS I/O Buffers
2- 21 2
Input Low (V)
1.075
Note:
Speed Grade
Note:
Std.
–1
–2
R
T
Z
Z
Z
*Measuring point = V
For the derating values at specific junction temperature and voltage supply levels, refer to
page
stub
0
0
Receiver
+
Commercial Temperature Range Conditions: T
Worst-Case VCCI = 2.3 V
Applicable to Pro I/Os
R
BLVDS/M-LVDS
Bus LVDS (BLVDS) and Multipoint LVDS (M-LVDS) specifications extend the existing LVDS standard to
high-performance multipoint bus applications. Multidrop and multipoint bus configurations can contain
any combination of drivers, receivers, and transceivers. Actel LVDS drivers provide the higher drive
current required by BLVDS and M-LVDS to accommodate the loading. The driver requires series
terminations for better signal quality and to control voltage swing. Termination is also required at both
ends of the bus, since the driver can be located anywhere on the bus. These configurations can be
implemented using TRIBUF_LVDS and BIBUF_LVDS macros along with appropriate terminations.
Multipoint designs using Actel LVDS macros can achieve up to 200 MHz with a maximum of 20 loads. A
sample application is given in
section in
Example: For a bus consisting of 20 equidistant loads, the following terminations provide the required
differential voltage, in worst-case industrial operating conditions at the farthest receiver: R
R
R
3-9.
S
T
-
= 70 Ω, given Z
EN
Timing Characteristics
R
Z
S
stub
Table
Z
Z
Z
0
0
stub
Transceiver
trip
2-168.
+
R
. See
T
t
0
S
DOUT
0.66
0.56
0.49
= 50 Ω (2") and Z
-
EN
R
Z
stub
S
Table 2-87 on page 2-168
Z
Z
Z
0
0
Figure
Input High (V)
stub
Driver
+
1.325
R
D
S
2-133. The input and output buffer delays are available in the LVDS
2.10
1.79
1.57
stub
-
t
EN
DP
R
Z
S
stub
= 50 Ω (~1.5").
R e visio n 1
Z
Z
Z
0
0
stub
J
for a complete table of trip points.
= 70°C, Worst-Case VCC = 1.425 V,
Receiver
+
R
R
S
0.04
0.04
0.03
-
t
EN
DIN
R
Z
S
stub
Measuring Point* (V)
Cross point
...
Z
Z
0
0
1.82
1.55
1.36
t
Transceiver
PY
+
R
T
S
-
EN
R
S
V
REF
BIBUF_LVDS
Table 3-7 on
S
Z
Z
Units
0
0
(typ.) (V)
= 60 Ω and
–
ns
ns
ns
R
T