sc9s12hy64j0vllr Freescale Semiconductor, Inc, sc9s12hy64j0vllr Datasheet - Page 228

• Manufacturer Part Number: sc9s12hy64j0vllr
• Description: S12 Microcontrollers Mcu 16-bit Hcs12 Cisc 32kb Flash 5v Tray
• Manufacturer: Freescale Semiconductor, Inc

S12 Clock, Reset and Power Management Unit (S12CPMU) Block Description
7.1.2
This subsection lists and briefly describes all operating modes supported by the S12CPMU.
7.1.2.1
The voltage regulator is in Full Performance Mode (FPM).
The Phase Locked Loop (PLL) is on.
The Internal Reference Clock (IRC1M) is on.
The API is available.
7.1.2.2
For S12CPMU Wait Mode is the same as Run Mode.
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PLL Engaged Internal (PEI)
— This is the default mode after System Reset and Power-On Reset.
— The Bus Clock is based on the PLLCLK.
— After reset the PLL is configured for 64MHz VCOCLK operation
— The reference clock for the PLL (REFCLK) is based on internal reference clock IRC1M
PLL Engaged External (PEE)
— The Bus Clock is based on the PLLCLK.
— This mode can be entered from default mode PEI by performing the following steps:
PLL Bypassed External (PBE)
— The Bus Clock is based on the Oscillator Clock (OSCCLK).
— This mode can be entered from default mode PEI by performing the following steps:
— The PLLCLK is still on to filter possible spikes of the external oscillator clock.
Post divider is 0x03, so PLLCLK is VCOCLK divided by 4, that is 16MHz and Bus Clock is
8MHz.
The PLL can be re-configured for other bus frequencies.
– Configure the PLL for desired bus frequency.
– Program the reference divider (REFDIV[3:0] bits) to divide down oscillator frequency if
– Enable the external oscillator (OSCE bit)
– Enable the external oscillator (OSCE bit)
– Wait for oscillator to start up (UPOSC=1)
– Select the Oscillator Clock (OSCCLK) as Bus Clock (PLLSEL=0).
Modes of Operation
Run Mode
Wait Mode
necessary.
MC9S12HY/HA-Family Reference Manual, Rev. 1.04
Freescale Semiconductor