MB95710M Series
MB95770M Series
Document Number: 002-09307 Rev. *D
Page 32 of 172
• DBG pin
Connect the DBG pin to an external pull-up resistor of 2 k
Ω
or above.
After power-on, ensure that the DBG pin does not stay at “L” level until the reset output is released.
The DBG pin becomes a communication pin in debug mode. Since the actual pull-up resistance depends on the tool
used and the interconnection length, refer to the tool document when selecting a pull-up resistor.
• RST pin
Connect the RST pin to an external pull-up resistor of 2 k
Ω
or above.
To prevent the device from unintentionally entering the reset mode due to noise, minimize the interconnection length
between a pull-up resistor and the RST pin and that between a pull-up resistor and the V
CC
pin when designing the
layout of the printed circuit board.
The PF2/RST pin functions as the reset input/output pin after power-on. In addition, the reset output of the PF2/RST
pin can be enabled by the RSTOE bit in the SYSC register, and the reset input function and the general-purpose I/O
function can be selected by the RSTEN bit in the SYSC register.
• Analog power supply
Always set the same potential to the AV
CC
pin and the V
CC
pin. When V
CC
is larger than AV
CC
, the current may flow
through the AN00 to AN07 pins.
• Treatment of power supply pins on the 8/12-bit A/D converter
Ensure that AV
CC
is equal to V
CC
and AV
SS
equal to V
SS
even when the 8/12-bit A/D converter is not in use.
Noise riding on the AV
CC
pin may cause accuracy degradation. Therefore, connect a ceramic capacitor of 0.1 µF (ap-
prox.) as a bypass capacitor between the AV
CC
pin and the AV
SS
pin in the vicinity of this device.
• C pin
Use a ceramic capacitor or a capacitor with equivalent frequency characteristics. The decoupling capacitor for the
V
CC
pin must have a capacitance equal to or larger than the capacitance of C
S
. For the connection to a decoupling
capacitor C
S
, see the diagram below. To prevent the device from unintentionally entering a mode to which the device
is not set to transit due to noise, minimize the distance between the C pin and C
S
and the distance between C
S
and
the V
SS
pin when designing the layout of a printed circuit board.
• Note on serial communication
In serial communication, reception of wrong data may occur due to noise or other causes. Therefore, design a printed
circuit board to prevent noise from occurring. Taking account of the reception of wrong data, take measures such as
adding a checksum to the end of data in order to detect errors. If an error is detected, retransmit the data.
C
Cs
DBG
RST
• DBG/RST/C pins connection diagram