RL78/G1P
CHAPTER 2 PIN FUNCTIONS
R01UH0895EJ0100 Rev.1.00
16
Nov 29, 2019
(2/2)
Function Name
I/O
Function
X1
Resonator connection for main system clock
X2
EXCLK
Input
External clock input for main system clock
V
DD
Positive power supply for all pins
V
SS
Ground potential for all pins
TOOLRxD
Input
UART reception pin for the external device connection used during flash memory programming
TOOLTxD
Output
UART transmission pin for the external device connection used during flash memory programming
TOOL0
I/O
Data I/O for flash Memory programmer/debugger
Caution The relationship between the voltage on P40/TOOL0 and the operating mode after release from the
reset state is as follows.
Table 2-2. Relationship between the Voltage on P40/TOOL0 and Operating Mode
After Release from the Reset State
P40/TOOL0 Operating
Mode
V
DD
Normal operating mode
0 V
Flash memory programming mode
For details, see 23.5 Programming Method.
Remark
Use bypass capacitors (about 0.1
μ
F) as noise and latch up countermeasures with relatively thick wires at
the shortest distance to V
DD
to V
SS
lines.