msx532 Fairchild Semiconductor, msx532 Datasheet - Page 10

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

www.fairchildsemi.com
RCA[0]
RCA[1]
RCA[2]
RCA[3]
RCA[4]
RCA[5]
RCA[6]
RCA[7]
Introduction
Signal
I/O Buffer Read Commands (Continued)
Description
RCA[0] is set to one if the I/O buffer is an input. It is zero if the I/O buffer is not configured as an input. Note that an
I/O buffer can be configured as an Input, Output, Input and Output (in bi-directional mode), or No Connect. All I/O
buffers default to inputs at power-on reset or following a global I/O buffer Reset command, so RCA[0] will read as
a one at reset.
RCA[1] is set to a one if the I/O buffer is an output. It is zero if the I/O buffer is not configured as an output. If
RCA[1:0] equal 00 the I/O buffer is configured as a No Connect. A No Connect means that the I/O pin of the MSX
device is not connected to the crosspoint array. RCA[1] will read as a zero at reset.
RCA[2] is set to a one if the I/O buffer is configured in Bus Repeater Mode. It is zero if the I/O buffer is not in Bus
Repeater Mode. Bus Repeater Mode will be disabled by default at reset, so RCA[2] will read as a zero.
RCA[3] is set to a one if the I/O buffer is configured as a registered input and is assigned to use its Input Clock 1.
It is zero if the I/O buffer is not using Input Clock 1. Input Clock 1 for each I/O buffer will vary depending upon the
quadrant of the device in which it resides. RCA[3] will read as a zero at reset.
RCA[4] is set to a one if the I/O buffer is configured as a registered input and is assigned to use its Input Clock 2.
It is zero if the I/O buffer is not using Input Clock 2. As with Input Clock 1, the source changes depending upon the
quadrant of the device in which the I/O buffer resides. RCA[4] will read as a zero at reset.
RCA[5] is set to a one if the I/O buffer is configured as a registered input and assigned to use Next Neighbor
Clocking. It is zero if Next Neighbor Clocking is disabled. Next Neighbor Clocking allows the I/O buffer to be regis-
tered using the next higher numbered Port number signal as its input clock source. Port 100 on the MSX devices
can use the signal from Port 101 for its input clock if this mode is enabled. Port 531’s Next Neighbor is Port 0. Next
Neighbor Clocking will be disabled by default at reset, so RCA[5] will read as a zero.
RCA[6] is set to a one if the I/O buffer is configured as a registered output and is assigned to use its Output Clock
1. It is zero if the I/O buffer is not using Output Clock 1. As with Input Clock 1 and 2, the Output Clocks will vary
depending upon the quadrant of the device in which the I/O buffer resides. In the case of the MSX devices, the
Output Clock 1 and Input Clock 1 for each I/O buffer have the same source, and the Output Clock 2 and Input
Clock 2 do as well. RCA[6] will read as a zero at reset.
RCA[7] is set to a one if the I/O buffer is configured as a registered output and is assigned to use its Output Clock
2. It is zero if the I/O buffer is not using Output Clock 2. As with Output Clock 1, the source changes depending
upon the quadrant of the device in which the I/O buffer resides. RCA[7] will read as a zero at reset.
RCA[0]
RCA[1]
RCA[2]
RCA[3]
RCA[4]
RCA[5]
RCA[6]
RCA[7]
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
(Continued)
I/O buffer not set to input
I/O buffer set to input (default)
I/O buffer not set to output (default)
I/O buffer set to output
I/O buffer not set to Bus Repeater Mode (default)
I/O buffer set to Bus Repeater Mode
Function
I/O buffer not set to registered input mode (default)
I/O buffer set to registered input mode
I/O buffer not using Input Clock Source 2 in RI mode (default)
I/O buffer using Input Clock Source 2 in RI mode
I/O buffer not using Next Neighbor Clock in RI mode (default)
I/O buffer using Next Neighbor Clock in RI mode
I/O buffer not using Output Clock Source 1 in RO mode (default)
I/O buffer using Output Clock Source 1 in RO mode
I/O buffer not using Output Clock Source 2 in RO mode (default)
I/O buffer using Output Clock Source 2 in RO mode
Function
Function
Function
Function
Function
Function
Function
TABLE 5. I/O Buffer Read Commands
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