Datasheet

 2000-2013 Microchip Technology Inc. DS30569C-page 127
PIC16F870/871
TABLE 14-1: EXTERNAL CLOCK TIMING REQUIREMENTS
Param
No.
Sym Characteristic Min Typ† Max Units Conditions
F
OSC External CLKI Frequency
(Note 1)
DC — 4 MHz XT and RC Osc mode
DC — 4 MHz HS Osc mode (-04)
DC — 20 MHz HS Osc mode (-20)
DC — 200 kHz LP Osc mode
Oscillator Frequency
(Note 1)
DC — 4 MHz RC Osc mode
0.1 — 4 MHz XT Osc mode
4
5
—
—
20
200
MHz
kHz
HS Osc mode
LP Osc mode
1
TOSC External CLKI Period
(Note 1)
250 — — ns XT and RC Osc mode
250 — — ns HS Osc mode (-04)
50 — — ns HS Osc mode (-20)
5——s LP Osc mode
Oscillator Period
(Note 1)
250 — — ns RC Osc mode
250 — 10,000 ns XT Osc mode
250 — 250 ns HS Osc mode (-04)
50 — 250 ns HS Osc mode (-20)
5——s LP Osc mode
2
TCY Instruction Cycle Time
(Note 1)
200 TCY DC ns TCY = 4/FOSC
3
TosL,
TosH
External Clock in (OSC1) High
or Low Time
100 — — ns XT oscillator
2.5 — — s LP oscillator
15 — — ns HS oscillator
4
TosR,
TosF
External Clock in (OSC1) Rise
or Fall Time
— — 25 ns XT oscillator
— — 50 ns LP oscillator
— — 15 ns HS oscillator
† Data in "Typ" column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Note 1: Instruction cycle period (T
CY) 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 oper-
ation and/or higher than expected current consumption. All devices are tested to operate at "min." values
with an external clock applied to the OSC1/CLKI pin. When an external clock input is used, the "Max."
cycle time limit is "DC" (no clock) for all devices.