PIC16C84-04/P Microchip Technology, PIC16C84-04/P Datasheet - Page 43

• Manufacturer Part Number: PIC16C84-04/P
• Description: MICRO CTRL 1KX14 EPR EEPR 18DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C84-04/P

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• Peripherals: POR, WDT
• Number Of I /o: 13
• Program Memory Size: 1.75KB (1K x 14)
• Program Memory Type: EEPROM
• Eeprom Size: 64 x 8
• Ram Size: 36 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 6 V
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 18-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification
• Data Converters: -
• Connectivity: -

8.7
On power-up (Figure 8-9, Figure 8-10, Figure 8-11 and
Figure 8-12) the time-out sequence is as follows: First
PWRT time-out is invoked after a POR has expired.
Then the OST is activated. The total time-out will vary
based
configuration bit status. For example, in RC mode with
TABLE 8-5
Since the time-outs occur from the POR reset pulse, if
MCLR is kept low long enough, the time-outs will
expire. Then bringing MCLR high, execution will begin
immediately (Figure 8-9). This is useful for testing
purposes or to synchronize more than one PIC16CXX
device when operating in parallel.
Table 8-6 shows the significance of the TO and PD bits.
Table 8-3 lists the reset conditions for some special
registers, while Table 8-4 lists the reset conditions for
all the registers.
TABLE 8-6
the PWRT disabled, there will be no time-out at all.
TO
Configuration
1997 Microchip Technology Inc.
1
0
x
0
0
1
1
XT, HS, LP
Oscillator
RC
PD
on
Time-out Sequence and Power Down
Status Bits (TO/PD)
1
x
0
1
0
1
0
oscillator
Power-on Reset
Illegal, TO is set on POR
Illegal, PD is set on POR
WDT Reset (during normal operation)
WDT Wake-up
MCLR Reset during normal operation
MCLR Reset during SLEEP or interrupt
wake-up from SLEEP
1024T
TIME-OUT IN VARIOUS
SITUATIONS
STATUS BITS AND THEIR
SIGNIFICANCE
Enabled
72 ms +
PWRT
72 ms
OSC
Power-up
configuration
Condition
1024T
Disabled
PWRT
—
OSC
and
1024T
Wake-up
SLEEP
from
PWRTE
—
OSC
8.8
A brown-out is a condition where device power (V
dips below its minimum value, but not to zero, and then
recovers. The device should be reset in the event of a
brown-out.
To reset PIC16C84 devices when a brown-out occurs,
external brown-out protection circuits may be built, as
shown in Figure 8-13 and Figure 8-14.
FIGURE 8-13: BROWN-OUT PROTECTION
FIGURE 8-14: BROWN-OUT PROTECTION
This brown-out circuit is less expensive, although less
accurate. Transistor Q1 turns off when V
certain level such that:
This circuit will activate reset when V
(Vz + 0.7V) where Vz = Zener voltage.
Reset on Brown-Out
33k
R1
R2
V
V
DD
DD
CIRCUIT 1
CIRCUIT 2
V
DD
10k
•
R1 + R2
Q1
PIC16C84
40k
40k
R1
MCLR
MCLR
V
V
DD
PIC16CXX
PIC16CXX
DS30445C-page 43
DD
DD
= 0.7V
goes below
DD
is below a
DD
)