R0E00008AKCE00EP38 Datasheet, PDF (30/35 Pages) Renesas Technology Corp – Microcomputer Development Environment System

E8a Emulator
7. Notes on Using the E8a Emulator
7.3 Debugging during a watchdog timer operation
When running the E8a emulator program, the program refreshes the watchdog timer. If memory access is executed
through memory reference or modification, the watchdog timer will be refreshed by the E8a emulator program.
Note that this timing will differ from the actual operational timing.
The E8a emulator sets each of bit 0 and bit 7 of the option function select register (OFS: 0FFFFh) to 1b. Although
these addresses can be rewritten and the changed values can be referred to in the memory window, etc., the changed
values for these bits (bit 0 and bit 7) are invalid.
- b0: Watchdog timer start select bit
- b7: Count source protection mode after reset select bit
1: Watchdog timer is stopped after reset.
1: Count source protect mode disabled after reset
Also, the E8a emulator sets the lower 4 bits of the option function select register 2 (OFS2: 0FFDBh) to 1111b.
- b1, b0: Watchdog timer underflow period set bit
- b3, b2: Watchdog timer refresh acknowledgement period set bit
11: 3FFFh
11: 100%
7.4 Power supply
(1) Consumption current
When the E8a emulator does not supply power to the user system, it consumes the power voltage of the user system
from several mA to more than 10 mA. This is because the user power supply drives 74LVC125, 74LVC1T45 and
74LVC2T45 to make the communication signal level match the user system power supply voltage.
(2) E8a emulator power supply
When writing a program with the E8a emulator for mass production processes, the program requires reliability, so
do not use the E8a emulator power supply function. Supply power separately to the user system according to the
allowable voltage for MCU writing. Voltage supplied from the E8a emulator depends on the quality of the USB
power supply of the PC, and as such, precision is not guaranteed.
REJ10J1739-0200 Rev.2.00 Jul. 03, 2009
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