PIC MCU timer1\timer0 maximum external clocking frequency

[D1_DRE]

Hello all

Please I have the following questions about clocking timer0 or timer1 using an external clocking signal (i.e on pin T0KI or T1KI):

1. what is the maximum frequency supported,

2. Can I supply it with 5Mhz or 9Mhz xtal and it will work

2. The block diagram of the timer says no but will the frequency from the external clock source be divided by 4 also?

Thanx

 

[bunalmis]

1. what is the maximum frequency supported,

Tcy = 4000/Fosc

no prescaler; FTOCKImax = 1000 / (Tcy+40) Mhz


with prescaler; FTOCKImax = 1000/ 20 = 50 Mhz

Syncron mode

FT1CKmax 33Mhz F series
FT1CKmax 20Mhz LF series


Asyncron mode

FT1CKmax 16Mhz F series
FT1CKmax 10Mhz LF series


2. Can I supply it with 5Mhz or 9Mhz xtal and it will work

Which PIC ?

2. The block diagram of the timer says no but will the frequency from the external clock source be divided by 4 also?

Look pic16f870.pdf.