Renesas RL78 Series User Manual page 793

RL78/G1D
26.4.2 Flash memory programming mode
To rewrite the contents of the code flash memory through serial programming, set the RL78 microcontroller to the flash
memory programming mode. To enter the mode, set as follows.
<Serial programming using the dedicated flash memory programmer>
Connect the RL78 microcontroller to a dedicated flash memory programmer. Communication from the dedicated
flash memory programmer is performed to automatically switch to the flash memory programming mode.
<Serial programming using an external device (UART communication)>
Set the TOOL0 pin to the low level, and then cancel the reset (see Table 26-4). After that, enter flash memory
programming mode according to the procedures <1> to <4> shown in Figure 26-7. For details, refer to the RL78
Microcontrollers (RL78 Protocol A) Programmer Edition Application Note (R01AN0815).
Table 26-4. Relationship between TOOL0 Pin and Operation Mode after Reset Release
Remark t
t
t
For details, see 30.11 Timing Specs for Switching Flash Memory Programming Modes.
R01UH0515EJ0120 Rev.1.20
Dec 16, 2016
TOOL0
V Normal operation mode
DD
0 V Flash memory programming mode
Figure 26-7. Setting of Flash Memory Programming Mode
<1>
RESET
TOOL0
t
SU
<1> The low level is input to the TOOL0 pin.
<2> The external reset ends (POR and LVD reset must end before the external reset ends.).
<3> The TOOL0 pin is set to the high level.
<4> Baud rate setting by UART reception is completed.
: The segment shows that it is necessary to finish specifying the initial communication
SUINIT
settings within 100 ms from when the resets end.
: How long from when the TOOL0 pin is placed at the low level until an external reset ends
SU
: How long to keep the TOOL0 pin at the low level from when the external and internal
HD
resets end (the flash firmware processing time is excluded)
Operation Mode
<2> <3>
723 µs + t
HD
processing time
1-byte data for setting mode
t
SUINIT
CHAPTER 26 FLASH MEMORY
<4>
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