Minimal System; Schematic; Serial Interface - Fujitsu ALL FR 460 Series Application Note

1 Minimal System

THIS CHAPTER GIVES AN EXAMPLE OF A MINIMUM HARDWARE SYSTEM

1.1 Schematic

The following graphic shows a schematic of a minimum hardware system. Note that for other
MCU families a different pinning is needed.
Below is an example of an asynchronous serial programming interface for single chip mode:
PC connection
+
5V/3V
100n
Vcc
V+
C1+
100n
C1-
MAX232
C2+
100n
C2-
V-
T1OUT R1IN
100n
1
6

1.2 Serial Interface

The "PC connection" section is only needed, if no 5V external serial data lines for
programming are existing. The MAX232 is a standard level shifter, which converts the 5V
levels of the MCU to ±12V RS232V24 levels and vice versa.
If you use a 3.3V MCU a MAX3232 is recommended.
Please consider, that the internal charge pumps of the level shifter can produce noise on the
+5 Volts line, which can influence the ADC, if AVCC and AVRH are directly (unfiltered)
connected to it.
Note: It may be in case of external noise at SCK4 pin that the synchronous programming
interface will be initialized instead of asynchronous interface. Make sure that the level at SCK4
pin is stable during the initialization of Flash loader.
MCU-AN-300033-E-V15
FR460 Hardware Set Up
Chapter 1 Minimal System
MCU system
100n
T1IN
R1OUT
32.768kHz
R2IN
T2IN
4MHz
Vss
5
9
VDD5 VDD35
SOT4
SIN4
X0A
12p
MB91F46x
12p
X1A
X0
10p
10p VCC18C
X1
VSS
- 6 - © Fujitsu Microelectronics Europe GmbH
HVDD5
AVCC5
AVRH 100n
AVSS
AVRL
2k
INITX
1n
MD0
MD1
MD2
100n 10I
HVSS
2k
RESET