upd78f0124m6gba1-8et Renesas Electronics Corporation., upd78f0124m6gba1-8et Datasheet - Page 406

• Manufacturer Part Number: upd78f0124m6gba1-8et
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

(1) Signal collision
(2) Malfunction of other device
406
If the dedicated flash programmer (output) is connected to a pin (input) of a serial interface connected to another
device (output), signal collision takes place. To avoid this collision, either isolate the connection with the other
device, or make the other device go into an output high-impedance state.
If the dedicated flash programmer (output or input) is connected to a pin (input or output) of a serial interface
connected to another device (input), a signal may be output to the other device, causing the device to
malfunction. To avoid this malfunction, isolate the connection with the other device.
µ
µ
µ
PD78F0124
PD78F0124
PD78F0124
Input pin
Pin
Pin
Figure 25-14. Signal Collision (Input Pin of Serial Interface)
In the flash memory programming mode, the signal output by the device
collides with the signal sent from the dedicated flash programmer.
Therefore, isolate the signal of the other device.
If the signal output by the
mode affects the other device, isolate the signal of the other device.
If the signal output by the dedicated flash programmer in the flash memory
programming mode affects the other device, isolate the signal of the other
device.
Figure 25-15. Malfunction of Other Device
Signal collision
CHAPTER 25
User’s Manual U16315EJ3V1UD
µ
PD78F0124 in the flash memory programming
Dedicated flash programmer
connection pin
Dedicated flash programmer
connection pin
Dedicated flash programmer
connection pin
Other device
Other device
Other device
PD78F0124
Output pin
Input pin
Input pin