ISL59532_07 Datasheet, PDF (20/24 Pages) Intersil Corporation – 32x32 Video Crosspoint

ISL59532
Enabling Outputs
The output enable control word is used to enable individual outputs. There are 32 channels to configure, so this is accomplished by
writing 4 serial words, each controlling a bank of eight outputs at a time. The bank is selected by bits B9 and B8. The output enable
control word format is:
TABLE 4. OUTPUT ENABLE FORMAT
B15 B14 B13 B12 B11 B10 B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
001000
0
001000
0
001000
1
001000
1
0
O₇
O₆
O₅
O₄
O₃
O₂
O₁
O₀
1
O₁₅
O₁₄
O₁₃
O₁₂
O₁₁
O₁₀
O₉
O₈
0
O₂₃
O₂₂
O₂₁
O₂₀
O₁₉
O₁₈
O₁₇
O₁₆
1
O₃₁
O₃₀
O₂₉
O₂₈
O₂₇
O₂₆
O₂₅
O₂₄
Setting the O_N bit = 0 tri-states the output. Setting the O_N bit = 1 enables the output if the Global Output Enable bit is also set (the
individual output enable bits are ANDed with the Global Output Enable bit before they are sent to the output stage).
Setting the Gain
The gain of each output may be set to x1 or x2 using the Gain Set word. It is in the same format as the output enable control word:
B15 B14 B13 B12 B11 B10 B9
010000
0
010000
0
010000
1
010000
1
TABLE 5. GAIN SET FORMAT
B8
B7
B6
B5
B4
B3
B2
B1
B0
0
G₇
G₆
G₅
G₄
G₃
G₂
G₁
G₀
1
G₁₅
G₁₄
G₁₃
G₁₂
G₁₁
G₁₀
G₉
G₈
0
G₂₃
G₂₂
G₂₁
G₂₀
G₁₉
G₁₈
G₁₇
G₁₆
1
G₃₁
G₃₀
G₂₉
G₂₈
G₂₇
G₂₆
G₂₅
G₂₄
Set G_N = 0 for a gain of x1 or 1 for a gain of x2.
Broadcast Mode
The Broadcast Mode routes one input to all 32 outputs. The broadcast control word is:
TABLE 6. BROADCAST FORMAT
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2
0
1
1
I₄
I₃
I₂
I₁
I₀
0
0
0
0
0
0
B1
B0
0
Enable Broadcast
0: Broadcast Mode Disabled
1: Broadcast Mode Enabled
I₄:I₀ form the 5-bit word indicating the input channel (0 to 31) to be sent to all 32 outputs. Set the Enable Broadcast bit (B0) = 1 to
enable Broadcast Mode, or to 0 to disable Broadcast Mode. When Broadcast Mode is disabled, the previous channel assignments
are restored.
Control Word
The ISL59532’s power-on reset disables all outputs and places the part in a low-power standby mode. To enable the device, the
following control word should be sent:
TABLE 7. CONTROL WORD FORMAT
B15 B14 B13 B12 B11 B10
B9
B8 B7 B6 B5 B4 B3 B2
B1
B0
111000
Clamp
00000 0 0
Power
Global Output Enable
0: Clamp Disabled
0: Standby 0: All outputs tristated
1: Clamp Enabled
1: Operational 1: Individual Output Enable bits control outputs
The Clamp bit enables the input clamp function, forcing the AC-coupled signal’s most negative point to be equal to V_REF.
Note: The Clamp bit turns the DC-Restore clamp function on or off for all channels - there is no DC-Restore on/off control for
individual channels. The DC-Restore function only works with signals with sync tips (composite video). Signals that do not have
sync tips (the Chroma/C signal in s-video and the Pb, Pr signals in Component video), will be severely distorted if run through a
DC-Restore/clamp function.
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FN7432.5
February 7, 2007