Datasheet

ManualsBrandsMICROCHIP TECHNOLOGY ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller SOIC 14 8-Bit 20 MHz I/O number 12

100

PIC16F684

12.0 SPECIAL FEATURES OF THE

CPU

The PIC16F684 has a host of features intended to

maximize system reliability, minimize cost through

elimination of external components, provide power

saving features and offer code protection.

These features are:

• Reset

- Power-on Reset (POR)

- Power-up Timer (PWRT)

- Oscillator Start-up Timer (OST)

- Brown-out Reset (BOR)

• Interrupts

• Watchdog Timer (WDT)

• Oscillator selection

• Sleep

• Code protection

• ID Locations

• In-Circuit Serial Programming

The PIC16F684 has two timers that offer necessary

delays on power-up. One is the Oscillator Start-up

Timer (OST), intended to keep the chip in Reset until

the crystal oscillator is stable. The other is the

Power-up Timer (PWRT), which provides a fixed delay

of 64 ms (nominal) on power-up only, designed to keep

the part in Reset while the power supply stabilizes.

There is also circuitry to reset the device if a brown-out

occurs, which can use the Power-up Timer to provide

at least a 64 ms Reset. With these three

functions-on-chip, most applications need no external

Reset circuitry.

The Sleep mode is designed to offer a very low-current

Power-Down mode. The user can wake-up from Sleep

through:

• External Reset

• Watchdog Timer Wake-up

• An interrupt

Several oscillator options are also made available to

allow the part to fit the application. The INTOSC option

saves system cost while the LP crystal option saves

power. A set of configuration bits are used to select

various options (see Register 12-1).

12.1 Configuration Bits

The Configuration bits can be programmed (read as

‘0’), or left unprogrammed (read as ‘1’) to select various

device configurations as shown in Register 12-1.

These bits are mapped in program memory location

2007h.

Note: Address 2007h is beyond the user program

memory space. It belongs to the special

configuration memory space

(2000h-3FFFh), which can be accessed

only during programming. See

“PIC12F6XX/16F6XX Memory Program-

ming Specification” (DS41204) for more

information.