PFS172 datasheet(40/92 Pages) PADAUK

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PFS172

8bit MTP MCU with 8-bit ADC

Page 40 of 92

PDK-DS-PFS172-EN_V000-May 8, 2020

5.6 16-bit Timer (Timer16)

A 16-bit hardware timer (Timer16) is implemented in the PFS172, the clock sources of Timer16 may come

from system clock (CLK), clock of external crystal oscillator (EOSC), internal high RC oscillator (IHRC),

internal low RC oscillator (ILRC), PA4 and PA0. A multiplex is used to select clock output for the clock source.

Before sending clock to the counter16, a pre-scaling logic with divided-by-1, 4, 16, and 64 is used for wide

range counting.

The 16-bit counter performs up-counting operation only. The counter initial values can be stored from

memory by stt16 instruction and the counting values can be loaded to memory by ldt16 instruction. A

selector is used to select the interrupt condition of Timer16, whenever overflow occurs, the Timer16 interrupt

can be triggered. The hardware diagram of Timer16 is shown as Fig.9. The interrupt source of Timer16

comes from one of bit 8 to 15 of 16-bit counter, and the interrupt type can be rising edge trigger or falling edge

trigger which is specified in the bit 4 of integs register (IO address 0x0C).

Fig.9: Hardware diagram of Timer16

When using the Timer16, the syntax for Timer16 has been defined in the .INC file. There are three

parameters to define the Timer16; 1

st parameter is used to define the clock source of Timer16, 2nd parameter

is used to define the pre-scalar and the last one is to define the interrupt source. The detail description is

shown as below:

T16M

IO_RW

0x06

$ 7~5: STOP, SYSCLK, X, PA4_F, IHRC, EOSC, ILRC, PA0_F

// 1

st par.

$ 4~3: /1, /4, /16, /64

// 2

nd par.

$ 2~0: BIT8, BIT9, BIT10, BIT11, BIT12, BIT13, BIT14, BIT15

// 3

rd par.

PA4

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