LMH2190 Datasheet, PDF (20/24 Pages) National Semiconductor (TI) – Quad Channel 27 MHz Clock Tree Driver with I2C Interface

TABLE 6. CLK4 Output Register
Address = 04H, type = R/W, reset value = 06H, 0000_0110, Bold face settings are the default configuration.
Field
Bits Description
CLK4 Load
[1-0]
Sets the drive strength of the clock output based on the capacitive load.
00 - 10pF to 15pF
01 - 15pF to 22.5pF
10 - 22.5pF to 33.5pF
11 - 33.5pF to 50pF
CLK_REQ4 Input Polarity
[2] Sets whether a logic low or high enables the clock output.
0 - Logic low enables the clock output.
1 - Logic high enables the clock output.
CLK_REQ4 Force ON Control
[3] Selects whether to use a clock request or I²C logic to enable the output.
0 - Use the clock request pin to control the output.
1 - Force the clock output to be enabled (Force ON).
CLK_REQ4 Force OFF Control
[4] Selects whether to use a clock request or I²C logic to disable the output.
0 - Use the clock request pin to control the output.
1 - Force the clock output to be disabled (Force OFF). ”Force OFF" overrides ”Force
ON".
CLK_REQ4 Pull down Resistor
[5] Selects whether an internal 200 kΩ pull down resistor on the clock request input to GND
is present.
0 - No internal pull down resistor is present.
1 - Internal 200 kΩ pull-down resistor is present.
Reserved
[6]
Reserved
[7]
Address = 05H, type = R
Field
Thermal Shutdown (TSD)
CLK_REQ1 Input Value
CLK_REQ2 Input Value
CLK_REQ3 Input Value
CLK_REQ4 Input Value
SCLK_REQ Output Value
Reserved
Reserved
TABLE 7. Status Register
Bits Description
[0] Indicates if a thermal shutdown event has occurred.
0 - Thermal shutdown has not occurred.
1 - Thermal shutdown has occurred
[1] Captures the state of the generated clock request input value.
0 - Generated clock request is low.
1 - Generated clock request is high.
[2] Captures the state of the generated clock request input value.
0 - Generated clock request is low.
1 - Generated clock request is high.
[3] Captures the state of the generated clock request input value.
0 - Generated clock request is low.
1 - Generated clock request is high.
[4] Captures the state of the generated clock request input value.
0 - Generated clock request is low.
1 - Generated clock request is high.
[5] Captures the state of the system clock request output value.
0 - System clock request is low.
1 - System clock request is high.
[6]
[7]
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