RL78G13 datasheet(45/46 Pages) RENESAS

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General Precautions in the Handling of MPU/MCU Products

The following usage notes are applicable to all MPU/MCU products from Renesas. For detailed usage notes on the

products covered by this manual, refer to the relevant sections of the manual. If the descriptions under General

Precautions in the Handling of MPU/MCU Products and in the body of the manual differ from each other, the

description in the body of the manual takes precedence.

1. Handling of Unused Pins

 Handle unused pins in accord with the directions given under Handling of Unused Pins in the manual.

 The input pins of CMOS products are generally in the high-impedance state. In operation with unused pin in

the open-circuit state, extra electromagnetic noise is induced in the vicinity of LSI, an associated

shoot-through current flows internally, and malfunctions occur due to the false recognition of the pin state as

an input signal become possible. Unused pins should be handled as described under Handling of Unused Pins

in the manual.

2. Processing at Power-on

 The state of the product is undefined at the moment when power is supplied.

 The states of internal circuits in the LSI are indeterminate and the states of register settings and pins are

undefined at the moment when power is supplied.

In a finished product where the reset signal is applied to the external reset pin, the states of pins are not

guaranteed from the moment when power is supplied until the reset process is completed.

In a similar way, the states of pins in a product that is reset by an on-chip power-on reset function are not

guaranteed from the moment when power is supplied until the power reaches the level at which resetting has

been specified.

3. Prohibition of Access to Reserved Addresses

 Access to reserved addresses is prohibited.

 The reserved addresses are provided for the possible future expansion of functions. Do not access these

addresses; the correct operation of LSI is not guaranteed if they are accessed.

4. Clock Signals

 After applying a reset, only release the reset line after the operating clock signal has become stable.

When switching the clock signal during program execution, wait until the target clock signal has

stabilized.

 When the clock signal is generated with an external resonator (or from an external oscillator) during a reset,

ensure that the reset line is only released after full stabilization of the clock signal. Moreover, when switching

to a clock signal produced with an external resonator (or by an external oscillator) while program execution is

in progress, wait until the target clock signal is stable.

5. Differences between Products

 Before changing from one product to another, i.e. to one with a different part number, confirm that the

change will not lead to problems.

 The characteristics of MPU/MCU in the same group but having different part numbers may differ because of

the differences in internal memory capacity and layout pattern. When changing to products of different part

numbers, implement a system-evaluation test for each of the products.

RL78G13 Datasheet(PDF) 45 Page - Renesas Technology Corp