Serial Asynchronous Flash Programming
Chapter 1 Background Information
© Fujitsu Microelectronics Europe GmbH
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MCU-AN-300012-E-V13
1 Background Information
This chapter gives some information for connection of the microcontroller to the PC and the
internal Boot ROM of the MCU.
1.1 Connection to PC
For serial asynchronous programming of the internal Flash, UART channel 4 is used on
MB91460 series flash devices. Therefore UART pins SIN4 (serial input) and SOT4 (serial
output) have to be connected to the PC’s COM port via RS232 transceiver.
The figure below shows an example for this connection. You can also connect the RS232
signals DTR or RTS to the reset input of the microcontroller for controlling the reset signal by
the programmer software.
Some terminal applications also need a connection between Pin 7 (RTS) and Pin 8 (CTS) on
connector side.
Figure 1: Example of UART connection
Figure 2: RS232 Signal Connection
1.2 Boot
ROM
The Boot ROM is a fixed start-up routine, which is executed always after the Reset
Cancellation Sequence of every INIT or RST reset if the device is configured with the mode
pins set to MD[2:0]=”000” (internal ROM/vector mode).
GND DTR RxD TxD
CTS RTS DSR
1
6
5
9
