RL78/G15 CHAPTER 20 ON-CHIP DEBUG FUNCTION
R01UH0959EJ0110 Rev.1.10 Page 685 of 765
Mar 7, 2023
20.2 Connecting External Device (that Incorporates UART)
The V
DD
, RESET
¯¯¯¯¯¯
, TOOL0, V
SS
, TOOLTxD, and TOOLRxD pins are used to communicate with the host machine on
board via the RL78 microcontroller and an external device (a microcontroller or ASIC) connected to a UART.
Communication between the external device and the RL78 microcontroller is established by serial communication via the
dedicated UART using the TOOLTxD and TOOLRxD pins of the RL78 microcontroller.
V
DD
V
DD
V
SS
RL78 microcontroller
GND
RESET_OUT
TxD
RxD TOOLTxD
TOOLRxD
PORT
TOOL0
External device
(such as microcontroller and ASIC)
______
RESET