Chapter 3 Modes of Operation
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
43
The clocks to the peripherals are controlled by SCGC registers in this mode. For lowest possible current
in WAIT mode, all peripherals which are not required must be clock gated before entering in this mode.
3.6
Stop Modes
One of the two stop modes (stop2 or stop3) is entered upon execution of a STOP instruction when the
STOPE bit in the system option 1 register (SOPT1) is set. In both the stop modes, the bus and the CPU
clocks are halted.
•
In stop3, the voltage regulator is in standby and ICS module can be configured to leave the
reference clocks running.
•
In stop2, the voltage regulator is in partial powerdown.
Chapter 11, “Internal Clock Source (S08ICSV3)
,” for more information.
If the STOPE bit is not set when the CPU executes a STOP instruction, the MCU does not enter either of
the stop modes and an illegal opcode reset is forced. Stop modes are selected by setting the appropriate
bits in the System Power Management Status and Control Registers, SPMSC1 and SPMSC2.
shows all control bits that affect the stop mode selection and the modes selected under various
conditions. The selected mode is entered following the execution of a STOP instruction.
3.6.1
Stop2 Mode
To enter stop2, execute a STOP instruction under the conditions as shown in
circuitry of the MCU is powered off in stop2 mode with an exception of the RAM, the low power
oscillator, RTC and the LCD module. Upon entering stop2 mode, all I/O pin control signals are latched so
that the pins retain their states during stop2. The LCD driver pins continue to drive the signals necessary
to display the LCD data.
To exit from stop2 mode, assert the wakeup pins (PTC6/RESET or PTF2/IRQ) or through RTC interrupt
or POR.
Table 3-1. Stop Mode Selection
Register
SOPT1
BDCSCR
SPMSC1
SPMSC2
Stop Mode
Bit name
STOPE
ENBDM
1
1
ENBDM is located in the BDCSCR that is only accessible through BDC commands, see
.”
LVDE
LVDSE
PPDC
0
x
x
x
Stop modes disabled; illegal opcode reset if STOP
instruction executed
1
1
x
x
Stop3 with BDM enabled
2
2
When in stop3 mode with BDM enabled, the S
IDD
is near the R
IDD
levels because internal clocks are enabled.
1
0
Both bits must be 1
x
Stop3 with voltage regulator active
1
0
Either bit a 0
0
Stop3 (with Voltage regulator in Standby)
1
0
Either bit a 0
1
Stop2
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Страница 26: ...Chapter 1 Device Overview MC9S08LG32 MCU Series Rev 5 26 Freescale Semiconductor...
Страница 40: ...Chapter 2 Pins and Connections MC9S08LG32 MCU Series Rev 5 40 Freescale Semiconductor...
Страница 96: ...Chapter 5 Resets Interrupts and General System Control MC9S08LG32 MCU Series Rev 5 96 Freescale Semiconductor...
Страница 296: ...Chapter 12 Serial Peripheral Interface S08SPIV4 MC9S08LG32 MCU Series Rev 5 296 Freescale Semiconductor...
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