Agilent Technologies L4400 manual Byte Ordering, Memory Input Operations

8L4450A 64-Bit Digital I/O with Memory and Counter

•STOP: The memory output is halted on the rising edge of the interrupt line.

•GATE: The interrupt line acts a a gate for the memory output. The bank can output when the interrupt line is asserted, and will stop when the interrupt line is de- asserted.

When you have set the polarity and mode, enable the interrupt using the SOURce:DIGital:INTerrupt:ENABle command.

Memory Input Operations

For memory input operations, the interrupt line is an output and is set on a pattern match or when the memory has been filled. You can set the interrupt line to be driven or open collector using the SENSe:DIGital:HANDshake:DRIVe command.

NOTE	The settings for drive mode, output drive level, and input threshold also
	apply to the bank’s handshake lines.

When set to ACTive the interrupt line will be driven by the instrument. The high output voltage is set for both the handshaking and interrupt line on a bank with the SOURce:DIGital:HANDshake:LEVel command.

When set to OCOLlector the interrupt line will be driven low, but will go to high impedance mode when in the ‘High’ state. The open collector mode requires external pull- ups.

The SENSe:DIGital:INTerrupt:MODE command sets the condition that will cause the interrupt to be asserted. When set to MFULl the interrupt is given when the memory is full. When set to COMPare the interrupt is asserted when the pattern is detected (see page page 215). When either condition is removed, the interrupt is de- asserted.

The interrupt line is enabled by the SENSe:DIGital:INTerrupt:ENABle command and the status can be checked using the SCPI Status System (refer to the Programmer's Reference Help file on the L4400 Product Reference CD- ROM).

Byte Ordering

When using buffered memory operations, the width of the data sets how the memory data is interpreted. Changing the width of the first channel in a bank invalidates any traces stored or captured.

Output Operations For output operations (see page 210), traces are put into memory using the TRACe:DATA:DIGital command.

214 L4400 User’s Guide