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How to write to the internal flash memory with the MCU in boot mode?

Latest Updated:09/09/2011

Question:

I cannot write to the internal flash memory with the MCU in boot mode.
Please indicate the points to check to solve this problem.

Answer:

Please check the following points.     
・Power-on reset is correct.
‐Reset signal is cleared after the oscillation is stabilized at the time of power-on.
‐The hardware stand-by pin (HSTBY) is not switched to Low at power-on if your MCU has a stand-by function.                 
・The mode pin is set to boot mode and FWE pin is set to High level.
・The watchdog timer overflow pin (WSTDVF) is pulled up.
・The serial port pins (incoming data input pins and send data output pins) are appropriate for boot mode.
・The serial port pins (incoming data input pins and send data output pins) are pulled up.
・Check the communication state.
‐The control command data from the host PC are input to the incoming data input pin at your bit rate.
‐The corresponding data toward the control command is output from the send data output pin at your bit rate.
・Check the operation capabilities with NMI fixed to High.
Suitable Products
SH7286
SH7285
SH7243
SH7214, SH7216
SH7239, SH7237
SH7211
SH7124, SH7125
SH7147
SH7146, SH7149
SH7131, SH7132, SH7136, SH7137
SH7083, SH7084, SH7085, SH7086