TTP258
TonTouchTM
Preliminary
S-4: Power saving mode (Sleep mode)
The CPU enters sleep mode is operated by writing CPU power saving register
(PS). During the power saving mode, CPU holds the internal status of the
system.
S-5: MCU System Operation Modes
The MCU has 3 operating modes, including high-speed operation, low speed
operation, sleep modes. After power on reset, the MCU will go into high-speed
operation mode automatically. After wake up from sleep mode, the MCU will
resume the last operation mode.
High speed operating
mode
OSCH on & OSCL on
H/L
Reset release
Low speed operating
mode
Reset
OSCH off & OSCL on
Reset
RESET
SLEEP/ wake up
SLEEP/ wake up
Reset
SLEEP mode
CPU stop
Figure: System Operation State Diagram
* Power saving mode condition & Release
Modes
High speed oscillator
High speed oscillator
CPU clock
Sleep mode
Stopped as H/L=0
Keep Operating as H/L=1
Stopped
CPU internal status
Memory, Flag, Register, I/O
Program counter
Stop & Retain the status
Retain the status
Hold the next executed address
Peripherals: Time base, Timers,
Interrupts
Keep Operating
Watch Dog Timer
Disable & cleared
Release Condition
Reset, external and internal INT sources, Input Wake-up
16’/04/06
Page 12 of 44
Ver.: 1.2
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