msx532 Fairchild Semiconductor, msx532 Datasheet - Page 12

• Manufacturer Part Number: msx532
• Description: 532 Port Digital Crosspoint Switch With Lvttl I/o S
• Manufacturer: Fairchild Semiconductor

www.fairchildsemi.com
Introduction
Crosspoint Programming
Connections between ports through the crosspoint array
can be quickly made or broken using the RC interface. The
two ports to be connected or disconnected are addressed
Unlike I/O buffer programming commands, which take
effect immediately upon execution of the command, cross-
point connections will only be made if the UPDATE signal
is asserted HIGH. The crosspoint programming command
loads the Loading SRAM cell in the selected crosspoint
array location with a one (in the case of a new connection)
or a zero (to break an existing connection). If the UPDATE
signal is asserted, the Loading SRAM cells contents are
immediately transferred to the Active SRAM cell and the
connection is made or broken. However, if the UPDATE
signal is held LOW, the new connection will not be made.
RCI[1:0]
RCI[1:0]
1
1
1
0 1
0
0
(Continued)
0
0
3
RCC[3:0]
3
2
1
RCC[3:0]
2
1
1
0
0
0
9
9
8
8
7
7
6
RCB[9:0]
Port #1
6
5
RCB[9:0]
5
4
4
3
3
2
2
1
1
12
0
using RCA[9:0] and RCB[9:0]. RCC[1] controls whether a
connection is made or broken. The two ports are con-
nected when RCC[1] is set to zero, and disconnected when
RCC[1] is set to one
The UPDATE signal can be used to control when the
switch matrix connections are reconfigured.
I/O Buffer Configuration Programming
Each port can be fully configured in a single RapidConfig-
ure cycle. The figure below shows how an I/O buffer is pro-
grammed using all of the signals on the RC interface. The
following table shows how each control bits (RCC[3:0] and
RCB[9:0]) are used. During an I/O buffer programming
command the RCA[9:0] signals address the port to be pro-
grammed (see Table 6: I/O buffer Programming Com-
mands)
0
9
9
8
8
7
I/O Buffer Address
7
6
RCA[9:0]
Port #2
6
5
RCA[9:0]
5
4
4
3
3
2
2
1
1
Inverted Output Clock
Inverted Input Clock
Invert Output
Input Clock Source
Output Clock Source
Input Enable Select
Output Enable Select
Input/Output Select
Bus Repeater Enable
I/O Buffer Configuration
0
Connect/Disconnect
(0-Connect, 1-Disconnect)
Crosspoint Program
0