Starting Up In Boot Mode (Sci Interface) - Renesas RX100 Series User Manual

RX13T Group
As shown in Figure 31.21 , set the format to 8-bit data, 1 stop bit, no parity, and LSB first to communicate with the serial
programmer.
Figure 31.21 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.
Table 31.8 lists the maximum communication bit rates for communication in boot mode (SCI interface).
Table 31.8 Conditions for Communication
Operating Voltage
2.7 V or higher, and lower than 3.0 V
3.0 V or higher, and 5.5 V or lower
31.8.1.2

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 the MD pin is 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 Figure 31.22 , keep the signal of each pin unchanged for 400 ms after the reset is released. Use resets
according to the range described in section 32.4.2, Reset Timing .
System power supply
RES#
MD
RXD1
TXD1
Figure 31.22 Wait Time until Communication Becomes Possible in Boot Mode (SCI Interface)
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
Start
D0 D1 D2
bit
Maximum Communication Bit Rate
500 kbps
2 Mbps
Low
High
High
D3 D4 D5 D6
400 ms or longer
31. Flash Memory (FLASH)
Stop
D7
bit
Communication starts
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