PIC18F2480_09 Datasheet, PDF (443/490 Pages) Microchip Technology – 28/40/44-Pin Enhanced Flash Microcontrollers with ECAN Technology, 10-Bit A/D and nanoWatt Technology

PIC18F2480/2580/4480/4580
FIGURE 28-7:
VDD
MCLR
Internal
POR
PWRT
Time-out
OSC
Time-out
Internal
Reset
Watchdog
Timer
Reset
I/O pins
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND
POWER-UP TIMER TIMING
30
33
32
31
34
34
FIGURE 28-8:
BROWN-OUT RESET TIMING
VDD
VIRVST
Enable Internal
Reference Voltage
Internal Reference
Voltage Stable
BVDD
35
36
VBGAP = 1.2V
TABLE 28-10: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER
AND BROWN-OUT RESET REQUIREMENTS
Param.
No.
Sym
Characteristic
Min Typ Max Units
Conditions
30
TMCL MCLR Pulse Width (low)
2
—
—
μs
31
TWDT Watchdog Timer Time-out Period
(no postscaler)
3.4
4.0
4.6
ms
32
TOST Oscillator Start-up Timer Period
1024 TOSC — 1024 TOSC — TOSC = OSC1 period
33
TPWRT Power-up Timer Period
55.6 65.5
75
ms
34
TIOZ I/O High-Impedance from MCLR
Low or Watchdog Timer Reset
—
2
—
μs
35
TBOR Brown-out Reset Pulse Width
200
—
—
μs VDD ≤ BVDD (see D005)
36
TIRVST Time for Internal Reference Voltage
—
20
50
μs
to become Stable
37
TLVD High/Low-Voltage Detect Pulse
Width
200
—
—
μs VDD ≤ VLVD
38
TCSD CPU Start-up Time
—
10
—
μs
39
TIOBST Time for INTOSC to Stabilize
—
1
—
μs
© 2009 Microchip Technology Inc.
DS39637D-page 443