Rev. 1.60
76
August 20, 2019
Rev. 1.60
77
August 20, 2019
BS66F340/BS66F350/BS66F360/BS66F370
Touch A/D Flash MCU with LED Driver
BS66F340/BS66F350/BS66F360/BS66F370
Touch A/D Flash MCU with LED Driver
SLOW Mode to NORMAL Mode Switching
In SLOW mode the system clock is derived from f
SUB
. When system clock is switched back to the
NORMAL mode from f
SUB
, the CKS2~CKS0 bits should be set to "000" ~"110" and then the system
clock will respectively be switched to f
H
~ f
H
/64.
However, if f
H
is not used in SLOW mode and thus switched off, it will take some time to re-
oscillate and stabilise when switching to the NORMAL mode from the SLOW Mode. This is
monitored using the HXTF bit in the HXTC register or the HIRCF bit in the HIRCC register. The
time duration required for the high speed system oscillator stabilization is specified in the A.C.
characteristics.
NORMAL Mode
SLOW Mode
CKS2~CKS0 = 000~110
SLEEP Mode
FHIDEN=0, FSIDEN=0
HALT instruction is executed
IDLE0 Mode
FHIDEN=0, FSIDEN=1
HALT instruction is executed
IDLE1 Mode
FHIDEN=1, FSIDEN=1
HALT instruction is executed
IDLE2 Mode
FHIDEN=1, FSIDEN=0
HALT instruction is executed
Entering the SLEEP Mode
There is only one way for the device to enter the SLEEP Mode and that is to execute the "HALT"
instruction in the application program with both the FHIDEN and FSIDEN bits in the SCC register
equal to "0". In this mode all the clocks and functions will be switched off except the WDT function.
When this instruction is executed under the conditions described above, the following will occur:
•
The system clock will be stopped and the application program will stop at the "HALT"
instruction.
•
The Data Memory contents and registers will maintain their present condition.
•
The I/O ports will maintain their present conditions.
•
In the status register, the Power Down flag PDF will be set, and WDT timeout flag TO will be
cleared.
•
The WDT will be cleared and resume counting as the WDT function is always enabled.