RENESAS TOOL NEWS
[Notes]E20 Emulator, E1 Emulator, E2 Emulator, E2 Emulator Lite

R20TS0279EJ0101
Rev.1.01
Feb. 16, 2018

OutlineWhen using the E20 emulator, E1 emulator, E2 emulator, or E2 emulator Lite (hereafter E2 Lite), note thefollowing points.
1. When using the large trace capacity or coverage function of the E20 emulator for the RX family
2. When using the large trace capacity or coverage function of the E20 emulator and the internal trace function ofE20, E1, E2, and E2 Lite for the RX family

1.

When Using the Large Trace Capacity or Coverage Function of the E20Emulator for the RX Family

1.1
➢

1.2
➢

1.3

Applicable ProductE20 emulator

Applicable MCUs
RX family: RX64M, RX65N, RX651, and RX71M groups

Details

When the large trace capacity or coverage function of the E20 emulator is used for the RX family, a user programruns out of control under certain conditions. Note that this phenomenon occurs only during debugging with theemulator, and does not occur during operation of the chip itself.

1.4Conditions

If both conditions (1) and (2) are met, this problem may occur depending on the condition of the trace buffer
embedded in MCU.
(1)

Either of the following functions is used.
(1-1) Large trace capacity
For e2 studio: The trace output mode is set to "trace priority".
For CS+: The external trace output is set to "trace output priority".
(1-2) Coverage function
For e2 studio: The acquisition mode is set to "trace priority".
For CS+: The coverage measurement method is set to "coverage measurement priority".

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Mar. 25, 2021

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RENESAS TOOL NEWS(2)"RTSD instruction or RTFI instruction" is placed immediately after the "BSR instruction or JSR instruction".
Example:_func_A:_func_B:::
BSR_func_B

RTSD #20, R8-R9; (1)RTS; (2)The RTSD instruction (2) is placed immediately after the BSR instruction (1).

In C programs, when call for another function is coded at the end of a function (as shown in the following
example), an instruction sequence (as shown in the preceding example) may be generated depending on thecompiler type and settings.
Example:void func_A(void) {void func_B(void) {::func_B();}}The specific instruction format of (2) in which this phenomenon occurs is as follows.

Instruction format of (2)RTSD src, dest-dest2
RTFI

When this phenomenon occurs, the branch destination for the execution of (2) becomes an address that isdifferent from the normal address, and the program runs out of control.

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Mar. 25, 2021

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RENESAS TOOL NEWS1.5

WorkaroundDo either of the following methods to change the settings so as not to satisfy the conditions of section 1.4 (1):- When using the large trace capacity
For e2 studio: The trace output mode is set to "trace priority". --> Change the setting to "CPU executionpriority".
For CS+: The external trace output is set to "trace output priority". --> Change the setting to "CPU executionpriority".
- When using the coverage function
For e2 studio: The acquisition mode is set to "trace priority". --> Change the setting to "CPU executionpriority".
For CS+: The coverage measurement method is set to "coverage measurement priority". --> Change the settingto "CPU execution priority".

1.6

Schedule for Fixing the Problem

This problem will be fixed in the next version of e 2 studio and CS+.

2.

2.1
➢2.2
➢

When Using the Large Trace Capacity or Coverage Function of the E20
Emulator and the Internal Trace Function of E20, E1, E2, and E2 Lite for the RX
FamilyApplicable Products
E20 emulator, E1 emulator, E2 emulator, and E2 emulator Lite

Applicable MCUs
RX family: MCU with RXv2 core and RXv3 core ** See below for details.
https://www.renesas.com/us/en/products/microcontrollers-microprocessors/rx-32-bit-performance-efficiencymcus/rx-features

2.3

Details

When the large trace capacity or coverage function of the E20 emulator and the internal trace function of E20, E1, E2,and E2 Lite are used for the RX family, if specific conditions are satisfied, trace information or coverage information
cannot be correctly acquired. Note that this phenomenon occurs only during debugging with the emulator, and does
not occur during operation of the chip itself.

R20TS0279EJ0101
Mar. 25, 2021

Rev.1.01

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RENESAS TOOL NEWS
2.4

Conditions

When the trace function or coverage function is enabled, if the time of branch instruction execution to branch to asmaller address overlaps with the time of interrupt acceptance, this phenomenon occurs.

Example: When branching to address (1) that is smaller than (3) in the following branch instruction of (3)and at the same time, accepting an interrupt
LOOP:

; (1)
:
SUB

r3, r4BNE

LABEL1; (2) (the first branch instruction after (1))

:
BNE

LOOP

; (3)

:
LABEL1::

When this phenomenon occurs, the operation will be as follows.

Function

Operation when this phenomenon occurs

Trace acquisition

The trace information of (1) to (2) (the first branch instruction after(1)) which was not actually executed is displayed additionally before
the trace information of the interrupt handler.

Coverageacquisition

It is displayed that all instructions from (1) to (3) have been executed(covered) regardless of the actual execution status.

For trace acquisition, if the same instruction sequence is output to the trace result before and after the interrupt
processing execution, it can be determined that this phenomenon may have occurred.
For coverage acquisition, there is no way to determine whether this phenomenon has occurred.

2.5

Workaround

There is no workaround for this problem.

2.6

Schedule for Fixing the Problem

We do not plan to fix the problem.

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Mar. 25, 2021

Rev.1.01

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RENESAS TOOL NEWS
Revision History
Rev.
1.00
1.01

Date
Feb. 16, 2018
Mar. 25,2021

Page
3Description
SummaryFirst edition issued
Applicable MCUsTOYOSU FORESIA, 3-2-24 Toyosu, Koto-ku, Tokyo 135-0061 Japan
Renesas Electronics Corporation■Inquiry
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TS Colophon 2.1

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Mar. 25, 2021

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