Datasheet

 2011-2013 Microchip Technology Inc. DS40001453E-page 359
PIC16(L)F1847
FIGURE 30-5: CLOCK TIMING
TABLE 30-7: CLOCK OSCILLATOR TIMING REQUIREMENTS
Standard Operating Conditions (unless otherwise stated)
Param.
No.
Sym. Characteristic Min. Typ† Max. Units Conditions
OS01 FOSC External CLKIN Frequency
(1)
DC — 0.5 MHz External Clock (ECL)
DC — 4 MHz
External Clock (ECM)
DC — 20 MHz
External Clock (ECH)
Oscillator Frequency
(1)
— 32.768 — kHz LP Oscillator
0.1 — 4 MHz XT Oscillator
1 — 4 MHz HS Oscillator
1 — 20 MHz HS Oscillator, V
DD > 2.7V
DC — 4 MHz EXTRC, V
DD > 2.0V
OS02 T
OSC External CLKIN Period
(1)
27 —  µs LP Oscillator
250 —
 ns XT Oscillator
50 —
 ns HS Oscillator
50 —
 ns External Clock (EC)
Oscillator Period
(1)
— 30.5 — µs LP Oscillator
250 — 10,000 ns XT Oscillator
50 — 1,000 ns HS Oscillator
250 — — ns EXTRC
OS03 T
CY Instruction Cycle Time
(1)
200 TCY DC ns TCY = 4/FOSC
OS04* TosH,
TosL
External CLKIN High
External CLKIN Low
2 — — µs LP Oscillator
100 — — ns XT Oscillator
20 — — ns HS Oscillator
OS05* TosR,
TosF
External CLKIN Rise
External CLKIN Fall
0 — — ns LP Oscillator
0 — — ns XT Oscillator
0 — — ns HS Oscillator
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
Note 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 con-
sumption. All devices are tested to operate at “min” values with an external clock applied to CLKIN pin. When an external
clock input is used, the “max” cycle time limit is “DC” (no clock) for all devices.
OSC1/CLKIN
OSC2/CLKOUT
Q4 Q1 Q2 Q3 Q4 Q1
OS02
OS03
OS04 OS04
OSC2/CLKOUT
(LP,XT,HS Modes)
(CLKOUT Mode)