ST72324BJ2 datasheet(102/188 Pages) STMICROELECTRONICS

102 / 188 page

On-chip peripherals

ST72324B

102/188

SPI Data I/O Register (SPIDR)

The SPIDR register is used to transmit and receive data on the serial bus. In a master

device, a write to this register will initiate transmission/reception of another byte.

Note:

During the last clock cycle the SPIF bit is set, a copy of the received data byte in the shift

buffer is actually being read.

While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR

Warning:

A write to the SPIDR register places data directly into the

shift register for transmission.

A read to the SPIDR register returns the value located in the buffer and not the content of

the shift register (see Figure 50).

2SOD

SPI Output Disable

This bit is set and cleared by software. When set, it disables the alternate function of

the SPI output (MOSI in master mode / MISO in slave mode).

0: SPI output enabled (if SPE = 1).

1: SPI output disabled.

SSM

SS Management

This bit is set and cleared by software. When set, it disables the alternate function of

the SPI SS pin and uses the SSI bit value instead. See Slave Select management

on page 93.

0: Hardware management (SS managed by external pin).

1: Software management (internal SS signal controlled by SSI bit. External SS pin

free for general-purpose I/O).

0SSI

SS Internal mode

This bit is set and cleared by software. It acts as a ‘chip select’ by controlling the

level of the SS slave select signal when the SSM bit is set.

0: Slave selected.

1: Slave deselected.

SPIDR

Reset value: undefined

654

R/W

Table 56.

SPICSR register description (continued)

Bit

Name

Function

ST72324BJ2 датащи(PDF) 102 Page - STMicroelectronics

ST72324BJ2 датащи(HTML) 102 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

датащи скачать

ссылки URL