Page 56 - DEC40053 Ebook_Timer
P. 56
ANSWER
Q U E S T I O N 2
calculation
i. T0CON = 0b00000001 = 0x01
ii. F = 1/4 x 20MHz= 5MHz
T=1/5MHz= 0.2μs (Square wave, 1 cycle)
iii. How many ticks in 50ms delay
Delay= Timer Period x NOC x prescaler
NOC=50ms/(0.2μs x 4)=62500= F424(hex)
iv. Find register value for TMR0H:TMR0L
FFFF-register value +1 =F424H ticks
register value =(FFFF - F424) +1
= 0BDC(hex)
**TMR0H= 0B(hex)
**TMR0L= DC(hex)
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