PIC12F508-I/P Microchip Technology, PIC12F508-I/P Datasheet - Page 49

• Manufacturer Part Number: PIC12F508-I/P
• Description: IC MCU FLASH 512X12 8DIP
• Manufacturer: Microchip Technology
• Series: PIC® 12Fr

Specifications of PIC12F508-I/P

• Program Memory Type: FLASH
• Program Memory Size: 768B (512 x 12)
• Package / Case: 8-DIP (0.300", 7.62mm)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• Peripherals: POR, WDT
• Number Of I /o: 5
• Ram Size: 25 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC12F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 25 B
• Interface Type: RS- 232/USB
• Maximum Clock Frequency: 4 MHz
• Number Of Programmable I/os: 6
• Number Of Timers: 1
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DV164101, DM163014, DV164120, DM163029
• Minimum Operating Temperature: - 40 C
• Package: 8PDIP
• Device Core: PIC
• Family Name: PIC12
• Maximum Speed: 4 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC162059 - HEADER INTRFC MPLAB ICD2 8/14PINDM163029 - BOARD PICDEM FOR MECHATRONICSDVA12XP080 - ADAPTER DEVICE FOR MPLAB-ICEAC124001 - MODULE SKT PROMATEII 8DIP/SOIC
• Eeprom Size: -
• Data Converters: -
• Connectivity: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

7.3.1
This Configuration bit, when unprogrammed (left in the
‘1’ state), enables the external MCLR function. When
programmed, the MCLR function is tied to the internal
V
Figure 7-6.
FIGURE 7-6:
7.4
The PIC12F508/509/16F505 devices incorporate an
on-chip Power-on Reset (POR) circuitry, which
provides an internal chip Reset for most power-up
situations.
The on-chip POR circuit holds the chip in Reset until
V
operation. To take advantage of the internal POR,
program the (GP3/RB3)/MCLR/V
tie through a resistor to V
(GP3/RB3). An internal weak pull-up resistor is
implemented using a transistor (refer to Table 10-2 for
the pull-up resistor ranges). This will eliminate external
RC components usually needed to create a Power-on
Reset. A maximum rise time for V
Section 10.0 “Electrical Characteristics” for details.
When the devices start normal operation (exit the
Reset
(voltage, frequency, temperature,...) must be met to
ensure operation. If these conditions are not met, the
devices must be held in Reset until the operating
parameters are met.
A simplified block diagram of the on-chip Power-on
Reset circuit is shown in Figure 7-7.
© 2009 Microchip Technology Inc.
MCLRE
DD
DD
GPWU/RBWU
and the pin is assigned to be an input only. See
has reached a high enough level for proper
condition),
Power-on Reset (POR)
MCLR ENABLE
device
MCLR SELECT
DD
, or program the pin as
operating
(GP3/RB3)/MCLR/V
PP
DD
pin as MCLR and
is specified. See
Internal MCLR
parameters
PP
PIC12F508/509/16F505
The Power-on Reset circuit and the Device Reset
Timer (see Section 7.5 “Device Reset Timer (DRT)”)
circuit are closely related. On power-up, the Reset latch
is set and the DRT is reset. The DRT timer begins
counting once it detects MCLR to be high. After the
time-out period, which is typically 18 ms, it will reset the
Reset latch and thus end the on-chip Reset signal.
A power-up example where MCLR is held low is shown
in Figure 7-8. V
bringing MCLR high. The chip will actually come out of
Reset T
In Figure 7-9, the on-chip Power-on Reset feature is
being used (MCLR and V
is programmed to be (GP3/RB3). The V
before the start-up timer times out and there is no prob-
lem in getting a proper Reset. However, Figure 7-10
depicts a problem situation where V
The time between when the DRT senses that MCLR is
high and when MCLR and V
value, is too long. In this situation, when the start-up
timer times out, V
value and the chip may not function correctly. For such
situations, we recommend that external RC circuits be
used to achieve longer POR delay times (Figure 7-9).
For additional information, refer to Application Notes
AN522 “Power-Up Considerations” (DS00522) and
AN607 “Power-up Trouble Shooting” (DS00607).
Note:
DRT
When the devices start normal operation
(exit the Reset condition), device operat-
ing parameters (voltage, frequency, tem-
perature, etc.) must be met to ensure
operation. If these conditions are not met,
the device must be held in Reset until the
operating conditions are met.
msec after MCLR goes high.
DD
is allowed to rise and stabilize before
DD
has not reached the V
DD
are tied together or the pin
DD
actually reach their full
DD
DS41236E-page 49
rises too slowly.
DD
is stable
DD
(min)