AN2159

SPI operations

Doc ID 11400 Rev 3

11/23

After the shifting phase, it is possible to read data, applying 32 serial clocks per data record.

Up to 8 data records can be read this way.

Eight 32-bit data registers in STPM01 store relevant measurement information (see related

datasheet for more details). Figure 5 shows the records structure and the information they

hold, the default sequence of reading.

The system that reads the data record from the STPM01 should check the integrity of each

data record. If the check fails, the reading should be repeated, but this time only the shifting

phase should be applied otherwise a new data would be latched into transmission latches

and previous reading would be incorrectly lost.

Figure 4.

Timing for reading data registers

t

2

t

1

t

4

t

3

t

6

t

5

t

8

t

7

SDA

SCL

SYN

SCS