PIC16LCR66T-10/SP View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16LCR66T-10/SP

8-Bit CMOS Microcontrollers

Microchip Technology 

PIC16C6X

7.3 Prescaler

Applicable Devices

61 62 62A R62 63 R63 64 64A R64 65 65A R65 66 67

An 8-bit counter is available as a prescaler for the

Timer0 module or as a postscaler for the Watchdog

Timer (WDT), respectively (Figure 7-6). For simplicity,

this counter is being referred to as “prescaler” through-

out this data sheet. Note that the prescaler may be

used by either the Timer0 module or the Watchdog

Timer, but not both. Thus, a prescaler assignment for

the Timer0 module means that there is no prescaler for

the Watchdog Timer, and vice-versa.

The PSA and PS2:PS0 bits (OPTION<3:0>) determine

the prescaler assignment and prescale ratio.

When assigned to the Timer0 module, all instructions

writing to the TMR0 register (e.g. CLRF TMR0,

MOVWF TMR0, BSF TMR0,bitx) will clear the pres-

caler count. When assigned to the Watchdog Timer, a

CLRWDT instruction will clear the Watchdog Timer and

the prescaler count. The prescaler is not readable or

writable.

Note:

Writing to TMR0 when the prescaler is

assigned to Timer0 will clear the prescaler

count, but will not change the prescaler

assignment.

FIGURE 7-6: BLOCK DIAGRAM OF THE TIMER0/WDT PRESCALER

CLKOUT (=Fosc/4)

Data Bus

RA4/T0CKI

pin

T0SE

0M

U

X

1

T0CS

1

M

0

U

X

PSA

SYNC

2

Cycles

8

TMR0 reg

Set flag bit T0IF

on Overflow

Watchdog

Timer

WDT Enable bit

0

M

U

1X

PSA

8-bit Prescaler

8

8 - to - 1MUX

0

1

MUX

WDT

Time-out

Note: T0CS, T0SE, PSA, PS2:PS0 are (OPTION<5:0>).

PS2:PS0

PSA

DS30234D-page 68

© 1997 Microchip Technology Inc.

Share Link: