PIC16F877-04/PT Microchip Technology, PIC16F877-04/PT Datasheet - Page 125

• Manufacturer Part Number: PIC16F877-04/PT
• Description: IC MCU FLASH 8KX14 EE 44TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F877-04/PT

• Core Size: 8-Bit
• Program Memory Size: 14KB (8K x 14)
• Core Processor: PIC
• Speed: 4MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 44-TQFP, 44-VQFP
• Controller Family/series: PIC16F
• No. Of I/o's: 33
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 368Byte
• Cpu Speed: 4MHz
• No. Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12.3
The PIC16F87X 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 12-4:
2001 Microchip Technology Inc.
MCLR
OSC1
V
DD
Note 1: This is a separate oscillator from the RC oscillator of the CLKIN 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
Time-out
Reset
WDT
10-bit Ripple Counter
10-bit Ripple Counter
BODEN
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 12-4. These bits are used in
software to determine the nature of the RESET. See
Table 12-6 for a full description of RESET states of all
registers.
A simplified block diagram of the On-Chip Reset Circuit
is shown in Figure 12-4.
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.
PIC16F87X
S
R
DS30292C-page 123
Q
Enable PWRT
Enable OST
Chip_Reset