Agilent Technologies L4400 manual Buffered I/O Operations, Buffered Memory Output

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

Buffered I/O Operations

Each of the two banks on the L4450A has its own memory that can be used to store patterns to output (traces) or to store input patterns. The width of the first channel in each bank controls the width of the memory operations.

Memory may be used as:

•64K x 8 bits

•64K x 16 bits

•32K x 32 bits

Buffered (Memory) Output

Each bank on the L4450A has its own memory for use in buffered transfers. Changing a bank from an input to an output will clear all memory for that bank. For buffered outputs, you download “traces” of digital data to the memory. Multiple traces (up to 32) can be downloaded into each bank. A specified trace is then output using the handshaking parameters set.

The general steps to output from memory are:

1Set the channel width and direction.

2Set the handshake mode.

3Set the trigger source.

4Set the number of times to output the trace.

5Load the trace(s) into memory.

6Set which trace to use.

7Enable the memory.

8Trigger the output.

Set the channel width and direction. Use the SOURce:DIGital:DATA command to set the channel width and set the channel as an output. Additionally, the data specified in the command will be the initial state of the data lines before the memory operation begins.

Set the handshake mode. You must use synchronous handshaking mode. You can use either an internal or external strobe (clock) to pace the outputs. Handshaking is described in more detail on page 203.

Set the trigger source. By default, the trigger source is set to use a software trigger. You can also use one of the interrupt lines (see page page 213) as a trigger source.

210 L4400 User’s Guide