AN2846 datasheet(18/35 Pages) STMICROELECTRONICS

18 / 35 page

Application guidelines

AN2846

18/35

Doc ID 15130 Rev 1

Figure 26 shows a 16-bit transmission example when the application is running in good

conditions:

●

Application is correctly supplied: /UVA, Bit 7 not activated

●

SCLT3-8 junction temperature less than 150 °C: /OTA, bit 6 not activated

●

Correct transmission: parity bits in accordance with input states

1.4.5

SPI timing definition

The four SPI signals involved: /CS, SCK, MOSI, MISO are described in Figure 27. A fifth

/MISO pin output signal is also present.

The typical SCK frequency is 1 MHz, but the SCLT3 can run at up to 2 MHz. The other more

important timing parameters are:

●

tD: Delay time. This is the delay time of MISO between SCK falling edge and MISO

change.

●

tS: Set up time. This is the minimum holding time of MOSI input data for its capture

before the SCK rising edge.

●

tH: Holding time. This is the minimum holding time of MOSI input data after the SCK

rising edge for its correct capture.

The most important rules to meet to perform a correct data transmission are:

●

tCL > tD + tS

●

tCH > tH.

Figure 27.

SPI timing definition.

DIS

/CS

MISO

MOSI

SCK

MSB

LSB

MSB

AN2846 Folha de dados(PDF) 18 Page - STMicroelectronics

AN2846 Folha de dados(HTML) 18 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

Folha de dados Download

Ligação URL