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MC9S12P128_10 Datasheet, PDF (198/566 Pages) Freescale Semiconductor, Inc – S12 Microcontrollers | |||
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S12 Clock, Reset and Power Management Unit (S12CPMU)
⢠High noise immunity due to input hysteresis and spike ï¬ltering.
⢠Low RF emissions with peak-to-peak swing limited dynamically
⢠Transconductance (gm) sized for optimum start-up margin for typical crystals
⢠Dynamic gain control eliminates the need for external current limiting resistor
⢠Integrated resistor eliminates the need for external bias resistor.
⢠Low power consumption: Operates from internal 1.8V (nominal) supply, Amplitude control limits
power
The Voltage Regulator (IVREG) has the following features:
⢠Input voltage range from 3.13V to 5.5V
⢠Low-voltage detect (LVD) with low-voltage interrupt (LVI)
⢠Power-on reset (POR)
⢠Low-voltage reset (LVR)
The Phase Locked Loop (PLL) has the following features:
⢠highly accurate and phase locked frequency multiplier
⢠Conï¬gurable internal ï¬lter for best stability and lock time.
⢠Frequency modulation for deï¬ned jitter and reduced emission
⢠Automatic frequency lock detector
⢠Interrupt request on entry or exit from locked condition
⢠Reference clock either external (crystal) or internal square wave (1MHz IRC1M) based.
⢠PLL stability is sufï¬cient for LIN communication, even if using IRC1M as reference clock
The Internal Reference Clock (IRC1M) has the following features:
⢠Trimmable in frequency
⢠Factory trimmed value for 1MHz in Flash Memory, can be overwritten by application if required
Other features of the S12CPMU include
⢠Clock monitor to detect loss of crystal
⢠Autonomous periodical interrupt (API)
⢠Bus Clock Generator
â Clock switch to select either PLLCLK or external crystal/resonator based Bus Clock
â PLLCLK divider to adjust system speed
⢠System Reset generation from the following possible sources:
â Power-on reset (POR)
â Low-voltage reset (LVR)
â Illegal address access
â COP time out
â Loss of oscillation (clock monitor fail)
â External pin RESET
S12P-Family Reference Manual, Rev. 1.13
198
Freescale Semiconductor
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