afs600 Actel Corporation, afs600 Datasheet - Page 149

• Manufacturer Part Number: afs600
• Description: Actel Fusion Programmable System Chips Mixed-signal Family With Optional Arm Support
• Manufacturer: Actel Corporation

At the system level, the skew circuit can be used in
applications
bidirectional data lines need to be coordinated. This
circuit, when selected, provides a timing margin that can
prevent bus contention and subsequent data loss or
transmitter overstress due to transmitter-to-transmitter
Figure 2-102 • Example of Implementation of Skew Circuits in Bidirectional Transmission Systems Using Fusion Devices
Figure 2-103 • Timing Diagram (bypasses skew circuit)
Skew or
Bypass
Skew
ENABLE(t1)
Transmitter 1: Fusion I/O
Transmitter 1: OFF
Transmitter 2: ON
where
EN(r1)
ENABLE (t2)
ENABLE (r1)
ENABLE (t1)
Delay (t1)
EN (b2)
Routing
EN (b1)
transmission
EN(b1)
Contention
activities
Bus
Bidirectional Data Bus
Transmitter
Transmitter 1: ON
ENABLE/
DISABLE
A d v an c ed v1 . 4
on
Transmitter 2: OFF
current shorts.
skew
communication system.
contention is created, and
shows how it can be avoided with the skew circuit.
circuit
EN(b2)
Actel Fusion Programmable System Chips
Figure 2-102
implementation
Transmitter 2: Generic I/O
Transmitter 1: OFF
Delay (t2)
Routing
Figure 2-103
Figure 2-104 on page 2-136
presents an example of the
in
ENABLE(t2)
shows how bus
a
bidirectional
2-135