Change Of After Power-On Reset; Maximum Time Required For Change Of Cpu Clock - NEC PD75402A User Manual

As the PCC is set in 0 by RESET input,
range is wide). For this reason, in a system with a slow supply voltage rise (such as a system with a high- capacitance
capacitor connected), correct operation is possible even when an adequate supply voltage cannot be attained after
a power-on reset.
5V
Supply
Voltage
0V
RESET Input Signal
CPU
Operation
Table 5-5 Maximum Time Required for Change of CPU Clock
PCC Before Change PCC After Change
0000
0010
0011
* When standby mode is not set until
60
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
is reset-started at the slowest speed (state in which the operating voltage
Fig. 5-15 Change of
Oscillator Low-Speed
Stabilization Operation
Time
Max. No. of Machine Cycles
Required for Change of
0010
0011
0000
0011
0000
0010
changes.
after Power-On Reset
Progran Change (By Program)
Start
High-Speed
Operation
Max. Time Required for Change of
1
1
8
8
16
16
* (When f = 4.19 MHz)
XX
15.3 s