PIC16F870T-I/SS Microchip Technology, PIC16F870T-I/SS Datasheet - Page 93

• Manufacturer Part Number: PIC16F870T-I/SS
• Description: IC MCU FLASH 2KX14 EE 28SSOP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F870T-I/SS

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 3.5KB (2K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 64 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SSOP
• For Use With: I3-DB16F871 - BOARD DAUGHTER ICEPIC3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

11.3
The PIC16F870/871 differentiates between various
kinds of RESET:
• Power-on Reset (POR)
• MCLR Reset during normal operation
• MCLR Reset during SLEEP
• WDT Reset (during normal operation)
• WDT Wake-up (during SLEEP)
• Brown-out Reset (BOR)
Some registers are not affected in any RESET condi-
tion. 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, on MCLR Reset during
FIGURE 11-4:
 2003 Microchip Technology Inc.
MCLR
OSC1
V
DD
Note 1: This is a separate oscillator from the RC oscillator of the CLKI pin.
RESET
RC OSC
On-chip
OST/PWRT
Brown-out
V
(1)
Module
Detect
DD
WDT
Reset
Rise
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
OST
PWRT
WDT
Time-out
Reset
10-bit Ripple Counter
10-bit Ripple Counter
BOREN
Power-on Reset
External
RESET
SLEEP
SLEEP, and Brown-out Reset (BOR). 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 situa-
tions, as indicated in Table 11-4. These bits are used in
software to determine the nature of the RESET. See
Table 11-6 for a full description of RESET states of all
registers.
A simplified block diagram of the On-Chip Reset Circuit
is shown in Figure 11-4.
These devices 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.
PIC16F870/871
S
R
DS30569B-page 91
Q
Enable PWRT
Enable OST
Chip_Reset