Renesas rl78 User Manual
RL78/G1A
CHAPTER 25 FLASH MEMORY
25.2.2 Communication mode
Communication between the external device and the RL78 microcontroller is established by serial communication using
the TOOLTxD and TOOLRxD pins via the dedicated UART of the RL78 microcontroller.
Transfer rate: 1 M, 500 k, 250 k, 115.2kbps
Figure 25-4. Communication with External Device
<R>
V
DD
/EV
DD0
Note 1
V
SS
/EV
SS0
Note 1
/REGC
Note 2
RESET
TOOLTxD
V
DD
GND
/RESET
RL78 microcontroller
RxD
TxD
External device
(such as microcontroller
and ASIC)
TOOL0
PORT
TOOLRxD
Notes 1. 64-pin product only.
2.
Connect REGC pin to ground via a capacitor (0.47 to 1
μ
F).
The external device generates the following signals for the RL78 microcontroller.
<R>
Table 25-3. Pin Connection
External Device
RL78 Microcontroller
Signal Name
I/O
Pin Function
Pin Name
V
DD
I/O V
DD
voltage generation/power monitoring
V
DD
, EV
DD0
GND
−
Ground V
SS
, EV
SS0
, REGC
Note
RESETOUT Output
Reset
signal
output
RESET
RxD Input Receive
signal
TOOLTxD
TxD Output
Transmit
signal
TOOLRxD
PORT Output Mode
signal
TOOL0
Note Connect REGC pin to ground via a capacitor (0.47 to 1
μ
F).
R01UH0305EJ0200 Rev.2.00
806
Jul 04, 2013