External Clock/Oscillator Timing Requirements

Figure 1. Clock Timing
Table 1.
Standard Operating Conditions (unless otherwise stated)
Param. No. Sym. Characteristic Min. Typ. † Max. Units Conditions
ECL Oscillator
OS1 FECL Clock Frequency 1 MHz  
OS2 TECL_DC Clock Duty Cycle 40 60 %  
ECH Oscillator
OS5 FECH Clock Frequency 32 MHz VDD ≥ 2.7V
16 MHz VDD < 2.7V
OS6 TECH_DC Clock Duty Cycle 40 60 %  
Secondary Oscillator
OS10 FSEC Clock Frequency 32.768 kHz (Note 4)
System Oscillator
OS20 FOSC System Clock Frequency 32 MHz (Note 2, Note 3)
OS21 FCY Instruction Frequency FOSC/4 MHz  
OS22 TCY Instruction Period 125 1/FCY ns  
Notes:
  1. 1.Instruction cycle period (TCY) equals four times the input oscillator time base period. All specified values are based on characterization data for that particular oscillator type under standard operating conditions with the device executing code. Exceeding these specified limits may result in an unstable oscillator operation and/or higher than expected current consumption. All devices are tested to operate at “min” values with an external clock applied to OSC1 pin. When an external clock input is used, the “max” cycle time limit is “DC” (no clock) for all devices.
  2. 2.The system clock frequency (FOSC) is selected by the “main clock switch controls” as described in the “Power Saving Operation Modes” section.
  3. 3.The system clock frequency (FOSC) must meet the voltage requirements defined in the “Standard Operating Conditions” section.