Datasheet

Chapter 3 Modes of Operation
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor 35
To maintain I/O states for pins configured as general-purpose I/O before entering stop2, the user must
restore the contents of the I/O port registers, which have been saved in RAM, to the port registers before
writing to the PPDACK bit. If the port registers are not restored from RAM before writing to PPDACK,
then the pins will switch to their reset states when PPDACK is written.
For pins that were configured as peripheral I/O, the user must reconfigure the peripheral module that
interfaces to the pin before writing to the PPDACK bit. If the peripheral module is not enabled before
writing to PPDACK, the pins will be controlled by their associated port control registers when the I/O
latches are opened.
3.6.3 On-Chip Peripheral Modules in Stop Modes
When the MCU enters any stop mode, system clocks to the internal peripheral modules are stopped. Even
in the exception case (ENBDM = 1), where clocks to the background debug logic continue to operate,
clocks to the peripheral systems are halted to reduce power consumption. Refer to Section 3.6.2, “Stop2
Mode,” and Section 3.6.1, “Stop3 Mode,” for specific information on system behavior in stop modes.
Table 3-2. Stop Mode Behavior
Peripheral
Mode
Stop2 Stop3
CPU Off Standby
RAM Standby Standby
Flash Off Standby
Parallel Port Registers Off Standby
ADC Off Optionally On
1
1
Requires the asynchronous ADC clock and LVD to be enabled, else in standby.
ACMP Off Optionally On
2
2
If ACGBS in ACMPSC is set, LVD must be enabled, else in standby.
MCG Off Optionally On
3
3
IRCLKEN and IREFSTEN set in MCGC1, else in standby.
IIC Off Standby
RTC Optionally On
4
4
RTCPS[3:0] in RTCSC does not equal to 0 before entering stop, else off.
Optionally On
4
SCI Off Standby
SPI Off Standby
TPM Off Standby
System Voltage Regulator Off Standby
XOSC Off Optionally On
5
I/O Pins States Held States Held
USB (SIE and Transceiver) Off Optionally On
6
USB 3.3 V Regulator Off Standby
USB RAM Standby Standby