NRF52811-QCAA-R datasheet(350/444 Pages) NORDIC

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Peripherals

ADDR

M-1

Stretch

Figure 132: The TWI master reading data from a slave

6.25.4 Master repeated start sequence

A typical repeated start sequence is one in which the TWI master writes two bytes to the slave followed by

reading four bytes from the slave. This example uses shortcuts to perform the simplest type of repeated

start sequence, i.e. one write followed by one read. The same approach can be used to perform a

repeated start sequence where the sequence is read followed by write.

The figure A repeated start sequence, where the TWI master writes two bytes followed by reading 4 bytes

from the slave on page 350 illustrates this:

ADDR

Figure 133: A repeated start sequence, where the TWI master

writes two bytes followed by reading 4 bytes from the slave

If a more complex repeated start sequence is needed and the TWI firmware drive is serviced in a low

priority interrupt it may be necessary to use the SUSPEND task and SUSPENDED event to guarantee that

the correct tasks are generated at the correct time. This is illustrated in A double repeated start sequence

using the SUSPEND task to secure safe operation in low priority interrupts on page 351.

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NRF52811-QCAA-R Datasheet(PDF) 350 Page - Nordic Semiconductor