Datasheet

RL78/L12 CHAPTER 14 LCD CONTROLLER/DRIVER
R01UH0330EJ0200 Rev.2.00 609
Dec 13, 2013
14.3.1 Peripheral enable register 0 (PER0)
PER0 enables or disables supplying the clock to the peripheral hardware. Clock supply to a hardware macro that is not
used is stopped in order to reduce the power consumption and noise.
When the LCD controller/driver is used in subsystem clock (f
SUB), be sure to set bit 7 (RTCEN) of this register to 1.
This register is set by using a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation sets this register to 00H.
Figure 14-2. Format of Peripheral Enable Register 0 (PER0)
Address: F00F0H After reset: 00H R/W
Symbol <7> 6 <5> <4> 3 <2> 1 <0>
PER0 RTCEN 0 ADCEN IICA0EN 0 SAU0EN 0 TAU0EN
RTCEN Real-time clock (RTC),
12-bit interval timer
LCD controller/driver, clock output/buzzer output controller
When subsystem clock (fSUB) is
selected
When subsystem clock (fSUB) is
not selected
0
Stops input clock supply.
• SFR used by the real-time
clock (RTC) and 12-bit
interval timer cannot be
written.
• The real-time clock (RTC)
and 12-bit interval timer are in
the reset status.
Stops input clock and
subsystem clock supply.
• SFR used by the LCD
controller/driver and clock
output/buzzer output
controller can be read and
written.
Enables input clock and main
system clock supply
• SFR used by the LCD
controller/driver and clock
output/buzzer output
controller can be read and
written.
1
Enables input clock supply.
• SFR used by the real-time
clock (RTC) and 12-bit
interval timer can be read and
written.
Enables input clock and
subsystem clock supply
• SFR used by the LCD
controller/driver and clock
output/buzzer output
controller can be read and
written.
Cautions 1. The subsystem clock supply to peripheral functions other than the real-time clock, 12-
bit interval timer, and LCD controller/driver can be stopped in HALT mode when the
subsystem clock is used, by setting the RTCLPC bit of the subsystem clock supply
mode control register (OSMC) to 1. In this case, set the RTCEN bit of the PER0 register
to 1 and the other bits (bits 0 to 6) to 0.
2. Be sure to set bits 1, 3, and 6 to “0”.
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