Renesas RL78/G1H User Manual

RL78/G1H CHAPTER 6 CLOCK GENERATOR
R01UH0575EJ0120 Rev. 1.20 Page 105 of 920
Dec 22, 2016
6.3.3 Clock operation status control register (CSC)
This register is used to control the operations of the high-speed system clock, high-speed on-chip oscillator
clock, and subsystem clock (except the low-speed on-chip oscillator clock).
The CSC register can be set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation sets this register to C0H.
Figure 6 - 4 Format of Clock operation status control register (CSC)
Caution 1. After reset release, set the clock operation mode control register (CMC) before setting the CSC
register.
Caution 2. Set the oscillation stabilization time select register (OSTS) before setting the MSTOP bit to 0 after
releasing reset. Note that if the OSTS register is being used with its default settings, the OSTS
register is not required to be set here.
Caution 3. To start X1 oscillation as set by the MSTOP bit, check the oscillation stabilization time of the X1 clock
by using the oscillation stabilization time counter status register (OSTC).
Caution 4. When starting XT1 oscillation by setting the XSTOP bit, wait for oscillation of the subsystem clock to
stabilize by setting a wait time using software.
Caution 5. Do not stop the clock selected for the CPU peripheral hardware clock (f
CLK) with the OSC register.
Caution 6. The setting of the flags of the register to stop clock oscillation (invalidate the external clock input)
and the condition before clock oscillation is to be stopped are as Table 6 - 2. Check the condition
before stopping clock before stopping the clock.
Address: FFFA1H After reset: C0H R/W
Symbol<7><6>54321<0>
CSCMSTOPXTSTOP00000HIOSTOP
MSTOP
High-speed system clock operation control
X1 oscillation mode External clock input mode Input port mode
0 X1 oscillator operating External clock from EXCLK pin is
valid
Input port
1 X1 oscillator stopped External clock from EXCLK pin is
invalid
XTSTOP
Subsystem clock operation control
XT1 oscillation mode External clock input mode Input port mode
0 XT1 oscillator operating External clock from EXCLKS pin
is valid
Input port
1 XT1 oscillator stopped External clock from EXCLKS pin
is invalid
HIOSTOP High-speed on-chip oscillator clock operation control
0 High-speed on-chip oscillator operating
1 High-speed on-chip oscillator stopped

Renesas RL78/G1H Specifications

General

Brand	Renesas
Model	RL78/G1H
Category	Microcontrollers
Language	English