CHAPTER 22 POWER-ON-RESET CIRCUIT
Page 758 of 920
Figure 22 - 3 Timing of Generation of Internal Reset Signal by Power-on-reset Circuit and Voltage Detector (2/3)
(2) LVD is interrupt & reset mode (option byte 000C1: LVIMDS1, LVIMDS0 = 1, 0)
Note 1.
The internal reset processing time includes the oscillation accuracy stabilization time of the high-speed on-chip oscillator
clock.
Note 2.
The high-speed on-chip oscillator clock and a high-speed system clock or subsystem clock can be selected as the CPU
clock. To use the X1 clock, use the oscillation stabilization time counter status register (OSTC) to confirm the lapse of the
oscillation stabilization time. To use the XT1 clock, use the timer function for confirmation of the lapse of the stabilization
time.
Note 3.
After the interrupt request signal (INTLVI) is generated, the LVILV and LVIMD bits of the voltage detection level register
(LVIS) are automatically set to 1. After INTLVI is generated, appropriate settings should be made according to
- 8 Setting Procedure for Operating Voltage Check and Reset
, taking into consideration that the supply voltage might
return to the high voltage detection level (V
LVDH
) or higher without falling below the low voltage detection level (V
LVDL
).
Note 4.
The time until normal operation starts includes the following LVD reset processing time after the LVD detection level
(V
LVDH
) is reached as well as the voltage stabilization wait + POR reset processing time after the V
POR
(1.51 V, TYP.) is
reached.
LVD reset processing time: 0 ms to 0.0701 ms (MAX.)
Remark
V
LVDH
, V
LVDL
:
LVD detection voltage
V
POR
:
POR power supply rise detection voltage
V
PDR
:
POR power supply fall detection voltage
Supply voltage (V
DD
)
V
POR
= 1.51 V (TYP.)
V
PDR
= 1.50 V (TYP.)
Operating voltage range lower limit
0 V
Internal reset signal
High-speed on-chip
oscillator clock (f
IH
)
High-speed
system clock (f
MX
)
(when X1 oscillation
is selected)
V
LVDH
V
LVDL
INTLVI
Voltage stabilization wait time + POR reset processing time:
1.64 ms (TYP.), 3.10 ms (MAX.)
Reset period
(oscillation stop)
LVD reset processing time
Note 5
Voltage stabilization wait time + POR reset processing time:
1.64 ms (TYP.), 3.10 ms (MAX.)
Operation stops
Wait for oscillation accuracy
stabilization
Note 1
Starting oscillation is specified by software
Starting oscillation is
specified by software
Normal operation
Note 2
(high-speed on-chip oscillator clock)
Normal operation
Note 2
(high-speed on-chip oscillator clock)
LVD reset processing time
Note 4
Wait for oscillation accuracy
stabilization
Note 1
Note 3
Operation
stops
CPU
Содержание RL78/G1H
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