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16-BIT TIMING OPERATIONS USING ST7262 OR ST7263B MCUs

Table 2. Time measurement range using ST7263B

1.3.2.2 Minimum Period

In the case of ST7263B, on each valid input capture, the 16-bit counter value is latched auto-

matically into the 16-bit input capture registers (TICxHR & TICxLR) without any additional soft-

ware routine. So compared to the ST7262, the ST7263B needs less time to store the input

capture parameters into temporary variables.

Using the same method as for the ST7262 (see Figure 13):

And with the following parameters:

chronise the interrupt flag with the internal CPU frequency).

Using the above values based on the software example:

> 82 * 0.125 µs

> 10.25 µs

So we can calculate the minimum period Tmin = 5.125 µs.

1.3.2.3 Period Measurement Comparison Chart

The following table can be used to select the best prescaler value for a precise time or fre-

quency measurement with the appropriate resolution.

Prescalers

Timer Frequency

Maxi Period

2

4 MHz

16,384 ms

0.250 µs

4

2 MHz

32,767 ms

0.500 µs

8

1 MHz

65,535 ms

1 µs