Retrieving Data (R15)

Captured data may be retrieved with one of three dump commands:

S	0x53	Sample dump (CSV format, analogue & digital data).
M	0x4D	Mixed memory dump (Binary format, analogue & digital data).
A	0x41	Analog memory dump (Binary format, analogue data).

Each time one of these commands is issued, a finite set of samples is dumped to the host via the serial port. The first dump (after a trace completes) starts at the last recorded sample address. Each subsequent dump continues where the previous one left off allowing the entire contents of capture memory to be uploaded to the host using multiple dump commands.

The size of each dump is determined by the values programmed to the Dump Size register R15 which ranges from 1 to 256 samples (the value 0 implies 256). The dump size should not be larger than the number of samples the host can accept in one hit without hardware handshake.

The format of the dumped data depends on the dump command used:

S	=>	<CR>DDAA,DDAA,DDAA,DDAA ... DDAA<CR> DD is an 8 bit digital/logic sample, and AA is an 8 bit analogue sample. Both are ASCII encoded as a pair of hex characters.
M	=>	dadadadadada ... da d is an 8 bit digital/logic sample, and a is an 8 bit analogue sample. Both are binary encoded as a single byte each.
A	=>	aaaaaaaaaaa ... a   a is an 8 bit analog sample binary encoded.

If suitable pre and post trigger delays are programmed, the capture buffers will be completely filled. By reading from the sample address at which capture stopped, and issuing the required number of dump commands, a contiguous dump from the first captured sample to the last can be uploaded to the host without reference to the sample address at all.

If less than a full buffer has been recorded, it is of course possible to program the sample address counter to start the first dump at any sample address regardless of where the most recent trace left off.