Specifications

mikroElektronika | Free Online Book | PIC Microcontrollers | Chapter 4: Timers
❍ 1 - Internal cycle clock (Fosc/4).
● T0SE - TMR0 Source Edge Select bit
❍ 0 - Increment on high-to-low transition on TMR0 pin; and
❍ 1 - Increment on low-to-high transition on TMR0 pin.
● PSA - Prescaler Assignment bit
❍ 0 - Prescaler is assigned to the WDT; and
❍ 1 - Prescaler is assigned to the TMR0 timer/counter.
● PS2, PS1, PS0 - Prescaler Rate Select bit
❍ Prescaler rate is adjusted by combining these bits
As seen in the table 4-1, the same combination of bits gives different prescaler rate for
the timer/counter and watch-dog timer respectively.
PS2 PS1 PS0 TMR0 WDT
0 0 0 1:2 1:1
0 0 1 1:4 1:2
0 1 0 1:8 1:4
0 1 1 1:16 1:8
1 0 0 1:32 1:16
1 0 1 1:64 1:32
1 1 0 1:128 1:64
1 1 1 1:256 1:128
Table 4-1 Prescaler Rate
The function of the PSA bit is shown in the two figures below:
Fig. 4-3 The function of the PSA bit 0
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