PIC16C432-I View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16C432-I

OTP 8-Bit CMOS MCU with LIN Transceiver

Microchip Technology 

PIC16C432

6.3.1

SWITCHING PRESCALER

ASSIGNMENT

The prescaler assignment is fully under software

control (i.e., it can be changed “on-the-fly” during

program execution). To avoid an unintended device

RESET, the following instruction sequence

(Example 6-1) must be executed when changing the

prescaler assignment from Timer0 to WDT.

EXAMPLE 6-1:

CHANGING PRESCALER

(TIMER0WDT)

1.BCF

2.CLRWDT

3.CLRF

4.BSF

5.MOVLW

6.MOVWF

7.CLRWDT

8.MOVLW

9.MOVWF

10.BCF

STATUS, RP0

TMR0

STATUS, RP0

'00101111’b

OPTION

'00101xxx’b

OPTION

STATUS, RP0

;Skip if already in

; Bank 0

;Clear WDT

;Clear TMR0 & Prescaler

;Bank 1

;These 3 lines (5, 6, 7)

; are required only

; if desired PS<2:0>

; are

; 000 or 001

;Set Postscaler to

; desired WDT rate

;Return to Bank 0

To change prescaler from the WDT to the TMR0

module, use the sequence shown in Example 6-2. This

precaution must be taken, even if the WDT is disabled.

EXAMPLE 6-2:

CHANGING PRESCALER

(WDTTIMER0)

CLRWDT

BSF

STATUS, RP0

MOVLW b'xxxx0xxx'

MOVWF OPTION_REG

BCF

STATUS, RP0

;Clear WDT and 

;prescaler

;Select TMR0, new 

;prescale value and

;clock source

TABLE 6-1: REGISTERS ASSOCIATED WITH TIMER0

Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2

Bit 1

Bit 0

Value on:

POR

Value on

All Other

RESETS

01h

TMR0 Timer0 module register

xxxx xxxx uuuu uuuu

0Bh/8Bh INTCON GIE PEIE T0IE INTE RBIE T0IF

INTF

RBIF 0000 000x 0000 000u

81h

OPTION RBPU INTEDG T0CS T0SE PSA

PS2

PS1

PS0 1111 1111 1111 1111

85h

TRISA

—

—

— TRISA4 TRISA3 TRISA2 TLINRX(2) TRISA0 ---1 1111 ---1 1111

Legend: — = Unimplemented locations, read as ‘0’, x = unknown, u = unchanged

Note 1: Shaded bits are not used by TMR0 module.

2: TLINRX must be set to ‘1’ at all times.

 2000-2013 Microchip Technology Inc.

Preliminary

DS41140C-page 31

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