UPD78F0411GA-GAM-AX Datasheet, PDF (516/564 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 24 FLASH MEMORY
(1) Signal collision
If the dedicated flash memory 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.
Figure 24-6. Signal Collision (Input Pin of Serial Interface)
78K0/LC3
Input pin
Signal collision
Dedicated flash memory
programmer connection pin
Other device
Output pin
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.
(2) Malfunction of other device
If the dedicated flash memory 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.
78K0/LC3
Pin
Figure 24-7. Malfunction of Other Device
Dedicated flash memory
programmer connection pin
Other device
Input pin
If the signal output by the 78K0/LC3 in the flash memory programming
mode affects the other device, isolate the signal of the other device.
78K0/LC3
Pin
Dedicated flash memory
programmer connection pin
Other device
Input pin
If the signal output by the dedicated flash memory programmer in the flash
memory programming mode affects the other device, isolate the signal of
the other device.
514
User’s Manual U18698EJ1V0UD