RL78/G1P
CHAPTER 23 FLASH MEMORY
R01UH0895EJ0100 Rev.1.00
680
Nov 29, 2019
23.5.2 Flash memory programming mode
To rewrite the contents of the flash memory, set the RL78/G1P in the flash memory programming mode. To enter the
mode, set as follows.
<When programming by using the dedicated flash memory programmer>
Communication from the dedicated flash memory programmer is performed to automatically switch to the flash
memory programming mode.
<When programming by using an external device>
Set the TOOL0 pin to the low level, and then cancel the reset. Keep the TOOL0 pin at the low level from the reset
ends to 1 ms + software processing end, and then use UART communication to send the data “00H” from the external
device. Finish UART communication within 100 ms after the reset ends.
Figure 23-8. Setting of Flash Memory Programming Mode
RESET
TOOL0
<1>
<2>
<3>
t
SUINIT
723
μ
s + t
HD
processing
time
t
SU
<4>
00H reception
(TOOLRxD, TOOLTxD mode)
<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> Setting of the flash memory programming mode by UART reception and complete the baud
rate setting.
Remark
t
SUINIT
: The segment shows that it is necessary to finish specifying the initial communication settings within
100 ms from when the resets end.
t
SU
:
How long from when the TOOL0 pin is placed at the low level until an external reset ends
t
HD
: How long to keep the TOOL0 pin at the low level from when the external and internal resets end
(except soft processing time)
For details, see
27.9 Timing of Entry to Flash Memory Programming Modes
.