S6E2CC/C5/C4/C3/C2/C1 Series Flash Programming Specification, Document Number: 002-04913 Rev. *D
66
When built-in high-speed CR oscillator is used as a source oscillation clock
shows a connection example of FLASH MCU Programmer when a built-in high-speed CR oscillator is used as
a source oscillation clock.
When neither crystal oscillator nor external clock is connected to X0/X1 pins, the built-in high-speed CR oscillator is
connected for communication.
When built-in high-speed CR oscillator is used, the communication baud rate will start with a baud rate of 9600[bps], and
then it will be changed to 115200[bps].
The following are the restrictions when built-in high-speed CR oscillator is used
Because the oscillation frequency of the built-in high-speed CR oscillator would fluctuate due to temperature and voltage
change, the allowable baud rate error range might be exceeded.
For using the built-in high-speed CR oscillator, see "Built-in CR Oscillation Specifications" in "Data Sheet" of the product
used.
If flash erase is executed to the flash memory that its flash security is enabled when built-in CR oscillator is used instead
of external crystal oscillator, serial communication will be disconnected after the erase operation and then CR trimming
data will be lost. When flash security is enabled, use external crystal oscillator.
Figure 3-4 Connection Example When Built-in High-speed CR Oscillator is Used
RS-232C
driver
P21/SIN0_0
VSS
P60
VCC
INITX
P22/SOT0_0
Note: The pull-up resistance values shown are for example. Select the most appropriate resistance values for each system.
MD1
MD0
Device
●
●
●
Serial write: 0
Serial write: 1
10
kΩ
●
10
kΩ
●
●
●
Serial write at UART
communication mode: 0
10
kΩ
10
kΩ
RS-232C
User system
