PIC12C508A-04I/P Microchip Technology, PIC12C508A-04I/P Datasheet - Page 40

• Manufacturer Part Number: PIC12C508A-04I/P
• Description: IC MCU OTP 512X12 8DIP
• Manufacturer: Microchip Technology
• Series: PIC® 12Cr

Specifications of PIC12C508A-04I/P

• Program Memory Type: OTP
• 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): 3 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC12C
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 25 B
• Maximum Clock Frequency: 4 MHz
• Number Of Programmable I/os: 5
• Number Of Timers: 1
• Operating Supply Voltage: 2.5 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: DVMCPA, ICE2000
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: ISPICR1 - ADAPTER IN-CIRCUIT PROGRAMMINGDVMCPA - KIT DVR BOARD EVAL SYSTEM MXDEV1DVA12XP080 - ADAPTER DEVICE FOR MPLAB-ICEAC124001 - MODULE SKT PROMATEII 8DIP/SOIC
• Eeprom Size: -
• Data Converters: -
• Connectivity: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC12C5XX
8.3.1
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 8-7. When pin GP3/MCLR/V
MCLR, the internal pull-up is always on.
FIGURE 8-7:
8.4
The PIC12C5XX family incorporates 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
tion. To take advantage of the internal POR, program
the GP3/MCLR/V
resistor to V
weak pull-up resistor is implemented using a transistor.
Refer to Table 11-1 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
details.
When the device starts normal operation (exits the
reset condition), device operating parameters (voltage,
frequency, temperature, ...) must be met to ensure
operation. If these conditions are not met, the device
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 8-8.
DS40139E-page 40
DD
DD
DD
, and the pin is assigned to be a GPIO. See
has reached a high enough level for proper opera-
is specified. See Electrical Specifications for
MCLR ENABLE
Power-On Reset (POR)
GP3/MCLR/V
DD
or program the pin as GP3. An internal
WEAK
PULL-UP
PP
MCLR SELECT
PP
pin as MCLR and tie through a
MCLRE
PP
is configured as
INTERNAL MCLR
The Power-On Reset circuit and the Device Reset
Timer (Section 8.5) 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 8-9. V
stabilize before bringing MCLR high. The chip will
actually come out of reset T
goes high.
In Figure 8-10, the on-chip Power-On Reset feature is
being used (MCLR and V
pin is programmed to be GP3.). The V
before the start-up timer times out and there is no
problem in getting a proper reset. However, Figure 8-
11 depicts a problem situation where V
slowly. The time between when the DRT senses that
MCLR is high and when MCLR (and V
reach their full value, is too long. In this situation, when
the start-up timer times out, V
V
guaranteed to function correctly. For such situations,
we recommend that external RC circuits be used to
achieve longer POR delay times (Figure 8-10).
For additional information refer to Application Notes
“ Power-Up Considerations” - AN522 and “ Power-up
Trouble Shooting ” - AN607.
DD
Note:
(min) value and the chip is, therefore, not
When the device starts normal operation
(exits the reset condition), device operating
parameters (voltage, frequency, tempera-
ture, etc.) must be meet to ensure opera-
tion. If these conditions are not met, the
device must be held in reset until the oper-
ating conditions are met.
DD
1999 Microchip Technology Inc.
DD
is allowed to rise and
are tied together or the
DD
DRT
has not reached the
msec after MCLR
DD
DD
DD
) actually
rises too
is stable