PIC16F87X
FIGURE 15-5: EXTERNAL CLOCK TIMING
Q4
Q1
Q2
Q3
Q4
4
Q1
OSC1
1
3
3
4
2
CLKOUT
TABLE 15-1: EXTERNAL CLOCK TIMING REQUIREMENTS
Parameter Sym Characteristic
No.
Min Typ†
Max
Units Conditions
FOSC External CLKIN Frequency
DC
DC
DC
DC
DC
0.1
—
—
—
—
—
—
4
4
MHz XT and RC osc mode
MHz HS osc mode (-04)
MHz HS osc mode (-20)
kHz LP osc mode
(Note 1)
20
200
4
Oscillator Frequency
(Note 1)
MHz RC osc mode
4
MHz XT osc mode
4
5
—
—
20
200
MHz HS osc mode
kHz LP osc mode
1
TOSC External CLKIN Period
250
250
50
—
—
—
—
ns XT and RC osc mode
ns HS osc mode (-04)
ns HS osc mode (-20)
µs LP osc mode
(Note 1)
—
—
5
—
—
Oscillator Period
(Note 1)
250
250
250
50
—
—
ns RC osc mode
—
10,000
250
250
—
ns XT osc mode
—
ns HS osc mode (-04)
ns HS osc mode (-20)
µs LP osc mode
—
5
—
2
3
TCY Instruction Cycle Time
200
TCY
DC
ns TCY = 4/FOSC
(Note 1)
TosL, External Clock in (OSC1) High 100
TosH or Low Time
—
—
—
—
—
—
—
—
—
25
50
15
ns XT oscillator
µs LP oscillator
ns HS oscillator
ns XT oscillator
ns LP oscillator
ns HS oscillator
2.5
15
—
4
TosR, External Clock in (OSC1) Rise
TosF or Fall Time
—
—
Legend: † 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 (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 the OSC1/CLKIN pin. When an external clock input is used, the "Max." cycle time limit is
"DC" (no clock) for all devices.
1999 Microchip Technology Inc.
DS30292B-page 159
MICROCHIP [ MICROCHIP ]
