UPD78F1502AGK-GAK-AX Datasheet, PDF (843/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
CHAPTER 25 REGULATOR
CHAPTER 25 REGULATOR
25.1 Regulator Overview
All 78K0R/Lx3 microcontroller products contain a circuit for operating the device with a constant voltage. At this time, in
order to stabilize the regulator output voltage, connect the REGC pin to VSS via a capacitor (0.47 to 1 μF).
Also, use a capacitor with good characteristics, since it is used to stabilize internal voltage.
The regulator output voltage is normally 2.4 V (TYP.), and in the low-power consumption mode, 1.8 V (TYP.).
25.2 Registers Controlling Regulator
(1) Regulator mode control register (RMC)
This register sets the output voltage of the regulator.
RMC is set with an 8-bit memory manipulation instruction.
Reset input sets this register to 00H.
Figure 25-1. Format of Regulator Mode Control Register (RMC)
Address: F00F4H After reset: 00H R/W
Symbol
7
6
5
4
3
2
1
0
RMC
RMC[7:0]
5AH
00H
Other than
above
Control of output voltage of regulator
Fixed to low-power consumption mode (1.8 V)
Switches normal power mode (2.4 V) and low-power consumption mode (1.8 V) according to the
condition (refer to Table 25-1)
Setting prohibited
Cautions 1. The RMC register can be rewritten only in the low-power consumption mode (refer to Table
25-1). In other words, rewrite this register during CPU operation with the subsystem clock
(fXT) while the high-speed system clock (fMX), the high-speed internal oscillation clock, and the
20 MHz internal high-speed oscillation clock (fIH20) are both stopped.
2. When using the setting fixed to the low consumption current mode, the RMC register can be
used in the following cases.
<When the high-speed internal oscillation clock (fIH = 8 MHz (TYP.) or fIH = 1 MHz (TYP.)) is
selected as the CPU clock>
fCLK ≤ 1 MHz and external oscillator (X1 clock (fX), external main system clock (fEX)) stop.
<When the X1 clock (fX) or external main system clock (fEX) is selected as the CPU clock>
fCLK ≤ 1 MHz, fX/fEX ≤ 5 MHz and the internal high-speed oscillator stop.
<When the subsystem clock (fSUB) is selected as the CPU clock>
Both the internal high-speed oscillator and external oscillator (fX/fEX ≤ 5 MHz) stop or either
one stops.
R01UH0004EJ0501 Rev.5.01
827
Jun 20, 2011