HD64F7144F50V Datasheet, PDF (756/932 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

23. Advanced User Debugger (AUD)
23.3 Branch Trace Mode
23.3.1 Overview
In this mode, the branch destination address is output when a branch occurs in the user program.
Branches may be caused by branch instruction execution or interrupt/exception processing, but no
distinction is made between the two in this mode.
23.3.2 Operation
Operation starts in branch trace mode when AUDRST is asserted, AUDMD is driven low, and
then AUDRST is negated.
Figure 23.2 shows an example of data output.
While the user program is being executed without branches, the AUDATA pins constantly output
0011 in synchronization with AUDCK.
When a branch occurs, after execution starts at the branch destination address in the PC, the
previous fully output address (i.e. for which output was not interrupted by the occurrence of
another branch) is compared with the current branch address, and depending on the result,
AUDSYNC is asserted and the branch destination address output after 1-clock output of 1000 (in
the case of 4-bit output), 1001 (8-bit output), 1010 (16-bit output), or 1011 (32-bit output). The
initial value of the compared address is H'00000000.
On completion of the cycle in which the address is output, AUDSYNC is negated and 0011 is
simultaneously output from the AUDATA pins.
If another branch occurs during branch destination address output, the later branch has priority for
output. In this case, AUDSYNC is negated and the AUDATA pins output the address after
outputting 10xx again (figure 23.3 shows an example of the output when consecutive branches
occur). Note that the compared address is the previous fully output address, and not an interrupted
address (since the upper address of an interrupted address will be unknown).
The interval from the start of execution at the branch destination address in the PC until the
AUDATA pins output 10xx is 1.5 or 2 AUDCK cycles.
Rev.4.00 Mar. 27, 2008 Page 710 of 882
REJ09B0108-0400