Chapter 1 Device Overview MC9S12ZVHY/MC9S12ZVHL Families
S12ZVHY/S12ZVHL Family Reference Manual Rev. 1.05
Freescale Semiconductor
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1.5.3.2
Internal RC Oscillator (IRC)
•
Trimmable internal reference clock.
— Frequency: 1 MHz; Trimmed accuracy over -40
C to 150
C junction temperature range:
1.3%
1.5.4
Main External Oscillator (XOSCLCP)
•
Loop control Pierce oscillator using 4 MHz to 20 MHz crystal
— Current gain control on amplitude output
— Signal with low harmonic distortion
— Low power
— Good noise immunity
— Eliminates need for external current limiting resistor
— Transconductance sized for optimum start-up margin for typical crystals
— Oscillator pins shared with GPIO functionality
1.5.5
32K External Oscillator
•
Low speed oscillator using 32 kHz to 40 kHz crystal
— Low power
— Good noise immunity
— Oscillator pins shared with GPIO functionality
1.5.6
System Integrity Support
•
Power-On Reset (POR)
•
Illegal address detection
•
Low-voltage detection and low voltage reset generation
•
Clock monitor
•
High temperature Interrupt
•
Computer Operating Properly (COP) watchdog
— Configurable as window COP for enhanced failure detection
— Can be initialized out of reset using option bits located in flash memory
•
Unimplemented opcode traps
•
Unprogrammed byte value (0xFF) defaults to SWI instruction
•
ECC support on embedded NVM and SRAM
1.5.7
Real Time Clock (RTC)
•
Basic Clock functions with separate counters for Hour, Minutes and Seconds.
