R01UH0823EJ0100 Rev.1.00
Page 1705 of 1823
Jul 31, 2019
RX23W Group
50. Flash Memory (FLASH)
As shown in
, set the format to 8-bit data, 1 stop bit, no parity, and LSB first to communicate with the serial
programmer.
Figure 50.25
Communication Format
Initial communication with the programmer is performed at 9,600 or 19,200 bps. The communication bit rate can be
changed after the MCU is connected with the programmer.
lists the maximum communication bit rates for communication in boot mode (SCI interface).
50.8.2.2
Starting Up in Boot Mode (SCI Interface)
To start the MCU in boot mode (SCI interface), a reset must be released by changing the RES# pin from low to high
while both of the MD pin and UB pin are low. After starting up in boot mode (SCI interface), wait at least 400 ms until
communication with the MCU is enabled in boot mode (SCI interface).
As shown in
, keep the signal of each pin unchanged for 400 ms after the reset is released. Use resets
according to the range described in
.
Figure 50.26
Wait Time until Communication Becomes Possible in Boot Mode (SCI Interface)
Table 50.11
Conditions for Communication
Operating Voltage
Maximum Communication Bit Rate
Lower than 3.0 V
500 kbps
3.0 V or higher
2 Mbps
Start
bit
D0
D1
D2
D3
D4
D5
D6
D7
Stop
bit
System power supply
RES#
MD
UB
RXD1
TXD1
Low or open
Low
High
High
Communication starts
400 ms or longer