MB90480 datasheet(17/120 Pages) FUJITSU | 16-bit Proprietary Microcontroller

17 / 120 page

MB90480/485 Series

Treatment of power supply pins on models with A/D converters

Even when the A/D converters are not in use, be sure to make the necessary connections AVCC

= AVRH = VCC,

and AVSS

= VSS.

Notes on Using Power Supply

Only the MB90485 series usually uses a 3 V power supply. By setting VCC3

= 3 V power supply and VCC5 = 5 V

power supply, P20 to P27, P30 to P37, P40 to P47 and P70 to P77 can be interfaced as 5 V power supplies

separately from the main 3 V power supply. Note that the analog power supplies (such as AVCC and AVSS) for

the A/D converter can be used only as 3 V power supplies.

10. Notes on Using External Clock

Even when using an external clock signal, an oscillation stabilization delay is applied after a power-on reset or

when recovering from sub-clock or stop mode. When using an external clock, 25 MHz should be the upper

frequency limit.

The following figure shows a sample use of external clock signals.

11. Treatment of NC pins

NC (internally connected) pins should always be left open.

12. Notes on during operation of PLL clock mode

On this microcontroller, if in case the crystal oscillator breaks off or an external reference clock input stops while

the PLL clock mode is selected, a self-oscillator circuit contained in the PLL may continue its operation at its

self-running frequency. However, Fujitsu will not guarantee results of operation if such failure occurs.

13. When the MB90480/485 series microcontroller is used as a single system

When the MB90480/485 series microcontroller is used as a single system, use connections so the X0A

= VSS,

and X1A

= Open.

14. Writing to Flash memory

For writing to Flash memory, always ensure that the operating voltage VCC is between 3.0 V and 3.6 V.

OPEN

MB90480 Datasheet(PDF) 17 Page - Fujitsu Component Limited.