8 CLOCK GENERATOR (CLG)
72
EPSON
S1C17001 TECHNICAL MANUAL
8.2 CPU Core Clock (CCLK) Control
The CLG module incorporates a clock gear to slow down the system clock to send to the S1C17 core. To reduce
power consumption, operate the S1C17 core with the slowest possible clock speed. The halt command can be ex-
ecuted to stop the clock feed from the CLG to the S1C17 core for power savings.
OSC3
CCLK
OSC1
Cock gear
(1/1 to 1/8)
Gate
S1C17 core
Gear selection
System clock
HALT
Figure 8.2.1: CCLK feed system
Clock gear settings
CCLKGR[1:0] (D[1:0]/CLG_CCLK register) is used to select the gear ratio to reduce system clock speeds.
∗
CCLKGR[1:0]
: CCLK Clock Gear Ratio Select Bits in the CCLK Control (CLG_CCLK) Register (D[1:0]/0x5081)
Table 8.2.1: CCLK gear ratio selection
CCLKGR[1:0]
Gear ratio
0x3
1/8
0x2
1/4
0x1
1/2
0x0
1/1
(Default: 0x0)
Clock feed control
The CCLK clock feed is stopped by executing the halt command. Since this does not stop the system clock, pe-
ripheral modules will continue to operate.
HALT mode is cleared by resetting, NMI, or other interrupts. The CCLK feed resumes when HALT mode is
cleared.
Executing the slp command suspends system clock feed to the CLG, thereby halting the CCLK feed as well.
Clearing SLEEP mode with an external interrupt restarts the system clock feed and the CCLK feed.
For more information on system clock control, refer to “7. Oscillator Circuit (OSC).”
Summary of Contents for S1C17001
Page 1: ...Technical Manual S1C17001 CMOS 16 BIT SINGLE CHIP MICROCONTROLLER ...
Page 33: ...4 POWER SUPPLY VOLTAGE 24 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 63: ...6 INITERRUPT CONTROLLER 54 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 87: ...8 CLOCK GENERATOR CLG 78 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 91: ...9 PRESCALER PSC 82 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 133: ...11 16 BIT TIMER T16 124 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 211: ...16 STOPWATCH TIMER SWT 202 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 219: ...17 WATCHDOG TIMER WDT 210 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 241: ...18 UART 232 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 277: ...20 I2 C 268 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 313: ...25 PACKAGE 304 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...