MC68HC908JK1 Datasheet, PDF (99/210 Pages) Motorola, Inc – MC68HC908JK1

Oscillator (OSC)
Low Power Modes
8.5.5 RC Oscillator Clock (RCCLK)
RCCLK is the RC oscillator output signal. Its frequency is directly
proportional to the time constant of the external R and C. Figure 8-2
shows only the logical relation of RCCLK to OSC1 and may not
represent the actual circuitry.
8.5.6 Oscillator Out 2 (2OSCOUT)
2OSCOUT is same as the input clock (XTALCLK or RCCLK). This signal
is driven to the SIM module and is used to determine the COP cycles.
8.5.7 Oscillator Out (OSCOUT)
The frequency of this signal is equal to half of the 2OSCOUT, this signal
is driven to the SIM for generation of the bus clocks used by the CPU
and other modules on the MCU. OSCOUT will be divided again in the
SIM and results in the internal bus frequency being one fourth of the
XTALCLK or RCCLK frequency.
8.6 Low Power Modes
The WAIT and STOP instructions put the MCU in low-power
consumption standby modes.
8.6.1 Wait Mode
The WAIT instruction has no effect on the oscillator logic. OSCOUT and
2OSCOUT continues to drive to the SIM module.
8.6.2 Stop Mode
The STOP instruction disables the XTALCLK or the RCCLK output,
hence OSCOUT and 2OSCOUT.
MC68H(R)C908JL3 — Rev. 1.0
MOTOROLA
Oscillator (OSC)
Technical Data
99