MB90340E Datasheet, PDF (24/84 Pages) Fujitsu Component Limited. – 16-bit Microcontroller

MB90340E Series
13. Stabilization of power supply voltage
A sudden change in the supply voltage may cause the device to malfunction even within the VCC supply voltage
operating range. Therefore, the VCC supply voltage should be stabilized. For reference, the supply voltage should
be controlled so that VCC ripple variations (peak- to-peak values) at commercial frequencies (50 MHz/60 MHz)
fall below 10% of the standard VCC supply voltage and the coefficient of fluctuation does not exceed 0.1 V/ms at
instantaneous power switching.
14. Port 0 to Port 3 Output During Power-on (External-bus Mode)
As shown below, when the power is turned on in External-Bus mode, there is a possibility that output signal of
Port 0 to Port 3 might be unstable irrespective of the reset input.
VCC
Port0 to Port3
1/2VCC
Port0 to Port3 outputs Port0 to Port3 outputs = Hi-Z
might be unstable
15. Notes on Using the CAN Function
To use the CAN function, please set the DIRECT bit of the CAN Direct Mode Register (CDMR) to 1.
16. Flash Security Function (except for MB90F346E)
A security bit is located in the area of the flash memory.
If protection code 01H is written in the security bit, the flash memory is in the protected state by security.
Therefore please do not write 01H in this address if you do not use the security function.
Refer to following table for the address of the security bit.
Flash memory size
Address of the security bit
MB90F347E
MB90F342E
MB90F349E
Embedded 1 Mbit Flash Memory
Embedded 2 Mbits Flash Memory
FE0001H
FC0001H
MB90F343E
MB90F345E
Embedded 3 Mbits Flash Memory
Embedded 4 Mbits Flash Memory
F90001H
F80001H
24