7.4.5. Value not traced packet

Value not traced packets comprise a Value not traced header byte, followed by an optional data address, as Figure 7.35 shows. The decompression software must work backwards from the final data transfer, using the Value not traced packets in combination with the Normal data packets, to determine which of the LSM values were traced.

Figure 7.35. Value not traced packet

To view this graphic, your browser must support the SVG format. Either install a browser with native support, or install an appropriate plugin such as Adobe SVG Viewer.

The data address is output if the address of the transfer is noncontiguous relative to the previous transfer, so that the address of subsequent data transfers in the LSM can be determined if they are traced. It therefore follows the same rules as for Normal data packets. See The A bit for more information.


If an LSM instruction is traced, instruction tracing continues until the LSM completes, even if TraceEnable is deasserted before the LSM completes. This means that instructions executed under an LSM are also traced, regardless of whether TraceEnable remains asserted. For more information, see Independent load/store unit.

Copyright © 1999-2002, 2004-2009, 2011 ARM Limited. All rights reserved.ARM IHI 0014Q