PIC14000-20/SS Microchip Technology, PIC14000-20/SS Datasheet - Page 78

• Manufacturer Part Number: PIC14000-20/SS
• Description: IC MCU OTP 4KX14 A/D 28SSOP
• Manufacturer: Microchip Technology
• Series: PIC® 14r

Specifications of PIC14000-20/SS

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C
• Peripherals: POR, Temp Sensor, WDT
• Number Of I /o: 20
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: OTP
• Ram Size: 192 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 6 V
• Data Converters: Slope A/D
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 28-SSOP
• Processor Series: PIC14000
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 192 B
• Interface Type: SPI, UART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 22
• Number Of Timers: 1
• Operating Supply Voltage: 2.7 V to 6 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: ICE2000
• Minimum Operating Temperature: 0 C
• On-chip Adc: 14 bit
• For Use With: 309-1025 - ADAPTER 28-SSOP TO 28-DIP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

PIC14000
Figure 10-6 shows a series resonant oscillator circuit.
This circuit is also designed to use the fundamental
frequency of the crystal. The inverter performs a
180-degree phase shift in a series resonant oscillator
circuit. The 330 k
feedback to bias the inverters in their linear region.
FIGURE 10-6: EXTERNAL SERIES
FIGURE 10-7: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
DS40122B-page 78
Note 1: This is a separate oscillator from the RC
MCLR
OSC1
V
74AS04
DD
330k
On-chip
oscillator of the CLKIN pin.
RC OSC
OST/PWRT
0.1 F
XTAL
V
Module
(1)
RESONANT CRYSTAL
OSCILLATOR CIRCUIT
detect
WDT
DD
74AS04
330k
rise
resistors provide the negative
OST
PWRT
10-bit Ripple counter
WDT
10-bit Ripple counter
Time-out
Power-on Reset
External
Reset
SLEEP
74AS04
To Other
Devices
PIC14000
OSC1
Preliminary
Enable PWRT
Enable OST
10.3
The PIC14000 differentiates between various kinds of
reset:
• Power-on Reset (POR)
• MCLR Reset during normal operation
• MCLR Reset during SLEEP
• WDT Reset (normal operation)
Some registers are not affected in any reset condition;
their status is unknown on POR and unchanged in any
other reset. Most other registers are reset to a “reset
state” on Power-on Reset (POR), on the MCLR and
WDT Reset, and on MCLR Reset during SLEEP. They
are not affected by a WDT Wake-up, which is viewed
as the resumption of normal operation. The TO and PD
bits are set or cleared differently in different reset situ-
ations as indicated in Table 10-3. These bits are used
in software to determine the nature of the reset. See
Table 10-5 for a full description of reset states of all reg-
isters.
A simplified block diagram of the on-chip reset circuit is
shown in Figure 10-7.
The devices all have a MCLR noise filter in the MCLR
reset path. The filter will detect and ignore small pulses.
It should be noted that a WDT Reset does not drive
MCLR pin low.
Reset
1996 Microchip Technology Inc.
S
R
Q
Chip_Reset