PD17012_15 Datasheet, PDF (28/320 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLERS WITH DIGITAL TUNING SYSTEM HARDWARE

µPD17012, 17P012
1.4 Notes on Using CE and INT Pins
The CE and INT pins have a function to set a test mode (for IC test) in which the internal operations of the
µPD17012 and 17P012 are tested, in addition to the functions listed in 1.1 Pin Function List.
In the µPD17P012, the INT pin functions alternately as the VPP pin for writing or verifying the program memory.
If a voltage higher than VDD is applied to either of these pins, the test mode is set. Therefore, if noise exceeding
VDD is applied to these pins even during normal operation, the test mode may be set by mistake, affecting normal
operation.
Noise may be superimposed on these pins if the length of the wiring of these pins is too long.
Therefore, keep the wiring length as short as possible. If noise is inevitable, take noise suppression measures
by using an external component as illustrated below.
• Connect a diode with low VF
between CE or INT and VDD
• Connect a capacitor between CE or INT and VDD
VDD
VDD
Diode with
low VF
VDD
CE, INT
VDD
CE, INT
26
Data Sheet U10101EJ4V0DS