ST72324BJ2 datasheet(92/188 Pages) STMICROELECTRONICS

92 / 188 page

On-chip peripherals

ST72324B

92/188

10.4.3

General description

Figure 50 shows the serial peripheral interface (SPI) block diagram. The SPI has three

registers:

–

SPI Control Register (SPICR)

–

SPI Control/Status Register (SPICSR)

–

SPI Data Register (SPIDR)

The SPI is connected to external devices through four pins:

–

MISO: Master In / Slave Out data

–

MOSI: Master Out / Slave In data

–

SCK: Serial Clock out by SPI masters and input by SPI slaves

–SS: Slave select: This input signal acts as a ‘chip select’ to let the SPI master

communicate with slaves individually and to avoid contention on the data lines.

Slave SS inputs can be driven by standard I/O ports on the master MCU.

Figure 50.

Serial peripheral interface block diagram

Functional description

A basic example of interconnections between a single master and a single slave is

illustrated in Figure 51.

The MOSI pins are connected together and the MISO pins are connected together. In this

way data is transferred serially between master and slave (most significant bit first).

SPIDR

Read Buffer

8-bit Shift Register

Write

Read

Data/Address bus

SPI

SPIE

SPE

MSTR

CPHA

SPR0

SPR1

CPOL

Serial clock

generator

MOSI

MISO

SCK

control

state

SPICR

SPICSR

Interrupt

request

Master

control

SPR2

SPIF WCOL

MODF

OVR

SSI

SSM

SOD

bit

ST72324BJ2 Datasheet(PDF) 92 Page - STMicroelectronics

ST72324BJ2 Datasheet(HTML) 92 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 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL