ST72334J4TC View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST72334J4TC

8-bit MCU for automotive with single voltage Flash/ROM memory, ADC, 16-bit timers, SPI, SCI interfaces

STMicroelectronics 

ST72334xx-Auto, ST72314xx-Auto, ST72124Jx-Auto

SERIAL COMMUNICATIONS INTERFACE (Cont’d)

13.5.5 Functional Description

13.5.5.1 Serial Data Format

The block diagram of the Serial Control Interface,

is shown in Figure 47. It contains six dedicated

registers:

Word length may be selected as being either 8 or 9

bits by programming the M bit in the CR1 register

(see Figure 47).

– 2 control registers (CR1 and CR2)

The TDO pin is in low state during the start bit.

– A status register (SR)

The TDO pin is in high state during the stop bit.

– A baud rate register (BRR)

– An extended prescaler receiver register (ERPR)

– An extended prescaler transmitter register (ETPR)

Refer to the register descriptions in Section 13.5.8

for the definitions of each bit.

An Idle character is interpreted as an entire frame

of “1”s followed by the start bit of the next frame

which contains data.

A Break character is interpreted on receiving ‘0’s

for some multiple of the frame period. At the end of

the last break frame the transmitter inserts an ex-

tra ‘1’ bit to acknowledge the start bit.

Transmission and reception are driven by their

own baud rate generator.

Figure 48. Word length programming

9-bit Word length (M bit is set)

Data Frame

Possible

Parity

Bit

Next Data Frame

Next

Start

Bit Bit0

Bit1

Bit2

Bit3

Bit4 Bit5

Bit6

Bit7 Bit8

Stop

Bit

Start

Bit

Start

Idle Frame

Bit

Break Frame

Extra Start

‘1’ Bit

8-bit Word length (M bit is reset)

Data Frame

Start

Bit Bit0 Bit1 Bit2 Bit3 Bit4 Bit5

Possible

Parity

Bit

Bit6

Bit7

Stop

Bit

Next Data Frame

Next

Start

Bit

Start

Idle Frame

Bit

Break Frame

Extra

‘1’

Start

Bit

88/150

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