Fujitsu MB86R01, Application Note

Page: 12 / 13

Chapter 6 Trace measurement
an-mb86r01-trace-rev0-01.doc - 12 - © Fujitsu Microelectronics Europe GmbH
6.3 Measurement
FME ran the same program several times with different trace options. The results of this are
shown in the table below.
Data Capture
Cycle
Accurate
Use
Timestamps
Prevent
Overflow Error*
Unknown
opcode*
PC only enabled enabled enabled 2 7
PC only enabled disabled enabled 0 6
PC only enabled disabled disabled 0 7
PC only disabled enabled disabled 0 0
PC only disabled enabled enabled 0 0
PC only disabled disabled disabled 0 0
Data only enabled enabled enabled 0 36
Data only disabled enabled enabled 0 5
Data only disabled disabled enabled 0 5
Data only disabled disabled enabled 0 4
Data only disabled disabled disabled 0 4
Address only enabled enabled enabled 0 7
Address only enabled disabled enabled 0 6
Address only enabled disabled disabled 0 10
Address only disabled disabled enabled 0 4
Address only disabled disabled disabled 0 4
Address and Data enabled enabled enabled 3 1
Address and Data enabled disabled enabled 150|0|0|80** 30|0|0|16
Address and Data disabled enabled enabled 55|63|61|56 0|12|147|14
Address and Data disabled disabled enabled 55|51|56 11|10|11
Address and Data disabled disabled disabled 50|51 0|10
* These are some example trace messages
Error:
Error: Trace is not byte aligned. Trace data is corrupt.
Error: Trace is no longer synchronized. Resynchronizing.
Error: Unexpected Out of Order data.
Unknown:
Unknown opcode at address 0x40001c18
** |x|x|x| are different trace capture passes
6.4 Interpretation
As already mentioned, the trace performance depends heavily on the trace data width. With
4 bit only the PC (program counter) can be traced reliably. Otherwise the internal FIFO
overflows and data is lost. Due to this, the trace output is corrupted and it is not possible to
reproduce the complete program flow. However if the error is isolated and filters are used, it
is possible to trace all data of interest.