Agilent Technologies 35670-90066 manual H10MHZ, H20MHZ, Hsync, Imode, Keyvalid

	Agilent 35670A	Voltages and Signals
		A99 Motherboard
FSELAn	Fast Bus Asynchronous Select — This line is low when an asynchronous fast bus cycle is in
	operation.
FSELSn	Fast Bus Synchronous Select — This line is low when a synchronous fast bus cycle is in
	operation. The A6 Digital assembly uses this signal to enable I/O to its gate arrays and to the
	A5 Analog assembly’s source attenuator DAC and dc offset DAC.
H10MHZ	10 MHz Clock — This is a 50% duty cycle, 9.961472 MHz clock. This clock is H20MHZ
	divided by 2.
H20MHZ	20 MHz Clock — This is a 50% duty cycle, 19.922944 MHz clock. This clock provides the
	timing for the analyzer.
HRNGA	Half Range A — In both the two channel and four channel analyzer, a high on this line turns on
	the channel 1 half range LED. This line goes high when the A1 or A2 Input assembly detects
	that the amplitude of the channel 1 input signal reached half the set range.
HRNGB	Half Range B — In a two channel analyzer, a high on this line turns on the channel 2 half range
	LED. In a four channel analyzer, a high on this line turns on the channel 3 half range LED.
	This line goes high when the A1 Input assembly detects that the amplitude of the channel 2
	input signal reached half the set range or when the A2 Input assembly detects that the
	amplitude of the channel 3 input signal reached half the set range.
HRNGC	Half Range C — In a four channel analyzer, a high on this line turns on the channel 2 half
	range LED. This line goes high when the A2 Input assembly detects that the amplitude of the
	channel 2 input signal reached half the set range. This line is only used in four channel
	analyzers.
HRNGD	Half Range D — In a four channel analyzer, a high on this line turns on the channel 4 half
	range LED. This line goes high when the A2 Input assembly detects that the amplitude of the
	channel 4 input signal reached half the set range. This line is only used in four channel
	analyzers.
HSYNC	Horizontal Synchronization — A high on this line causes the external monitor to do a
	horizontal retrace. The Motherboard buffers this signal and routes it to the EXT MONITOR
	connector.
IFCn	Interface Clear — This line is only used during the analyzer’s development.
IMODE	Input Mode — This line indicates the A98 Power Supply assembly’s input power mode. When
	this line is high, the Power Supply assembly is operating on ac power. When this line is low,
	the Power Supply assembly is operation on dc power.
INTHPIBn	GPIB Controller Interrupt — A low on this line interrupts the A7 CPU assembly. This line is
	controlled by the A10 Rear Panel assembly’s GPIB controller.
INTONIXn	Parallel Port Interrupt — A low on this line interrupts the A7 CPU assembly. This line is
	controlled by the A10 Rear Panel assembly’s parallel port controller.
KEYVALID	Key Valid — A high on this line interrupts the A7 CPU assembly. This line goes high when a
	key is pressed on an external keyboard.

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