User`s manual

SuperH™ Family E10A-USB Emulator Section 2 Software Specifications when Using the Emulator
REJ10J1941-0300 Rev. 3.00 Page 41 of 46
Aug 25, 2010
Regarding Errors in Measurement
Errors in the results of the performance measurement function for numbers of cycles of execution
are incurred immediately before the start of execution and immediately after a break. The errors
differ according to the conditions that are in use. The procedure for evaluating the error is
described below.
Procedure
Execute an NOP instruction in the internal RAM area and measure the error by calculating the
difference between the result for the number of cycles of execution and the logical value.
This is explained below with an example for the location H'FFF80000 in the internal RAM area
and one read cycle set for the RAM area.
1. Change H'FFF80000 to an NOP instruction.
2. Set the PC to H'FFF80000 in the [Register] window.
3. Set the measurement condition for Ch1 to Elapsed time (the number of cycles for
execution) in the [Performance Analysis] window.
4. Click on the [Step in] button of the High-performance Embedded Workshop.
5. Check the value in the performance counter following the break.
Executing an NOP instruction in the internal RAM area entails one cycle for reading from that
area, so the logical value for the number of cycles will be 1.
When the counter value for the number of cycles is 42, the error can be acquired from the
following formula.
Result of the measured number of cycles for execution – logical value of the number of cycles
(number of cycles of access to the internal RAM) = 42 - 1 = 41
Note: When [Ch2 to Ch1 PA] or [Ch1 to Ch2 PA] is selected, to execute the user program,
specify conditions set in Event Condition 2 and Event Condition 1 and one or more items
for performance measurement.
(b) Measurement Item
Items are measured with [Channel 1 to 4] in the [Performance Analysis] dialog box. Maximum
four conditions can be specified at the same time.