Samsung S3F80JB - Manual (Page 230)

RESET S3F80JB
8-12
SOURCES TO RELEASE STOP MODE
Stop mode is released when following sources go active:
— System Reset by external reset pin (nRESET)
— System Reset by Internal Power-On Reset (IPOR)
— Low Voltage Detector (LVD)
— External Interrupt (INT0-INT9)
— SED & R circuit
Using nRESET Pin to Release STOP Mode
Stop mode is released when the system reset signal goes active by nRESET Pin: all system and peripheral
control registers are reset to their default hardware values and the contents of all data registers are retained.
When the oscillation stabilization interval has elapsed, the CPU starts the system initialization routine by fetching
the program instruction stored in reset address.
Using IPOR to Release STOP Mode
Stop mode is released when the system reset signal goes active by internal power-on reset (IPOR). IPOR is
enabled when IPOR/LVD Control Bit is set to ‘0’, and chip status is in stop mode by executing ‘STOP’ instruction. :
All system and peripheral control registers are reset to their default hardware values and contents of all data
registers are unknown states. When the oscillation stabilization interval has elapsed, the CPU starts the system
initialization routine by fetching the program instruction stored in reset address.
Using LVD to Release STOP Mode
When IPOR/LVD Control Bit (smart option bit [7] @ 03FH) is set to ‘1’, and VDD is changed in condition for LVD
operation in stop mode, stop mode is released and reset occurs.
Using an External Interrupt to Release STOP Mode
External interrupts can be used to release stop mode. When IPOR/LVD Control Bit (smart option bit [7] @ 03FH)
is set to ‘0’ and external interrupt is enabled, S3F80JB is released stop mode and generated reset signal. On the
other hand, when IPOR/LVD Control Bit (smart option bit [7] @ 03FH) is set to ‘1’, S3F80JB is only released stop
mode and isn’t generated reset signal. To wake-up from stop mode by external interrupt from INT0 to INT9,
external interrupt should be enabled by setting corresponding control registers or instructions.
Please note the following conditions for Stop mode release:
— If you release Stop mode using an external interrupt, the current values in system and peripheral control
registers are unchanged.
— If you use an external interrupt for Stop mode release, you can also program the duration of the oscillation
stabilization interval. To do this, you must make the appropriate control and clock settings before entering
Stop mode.
— If you use an interrupt to release Stop mode, the bit-pair setting for CLKCON.4/CLKCON.3 remains
unchanged and the currently selected clock value is used.