Справочник Пользователя для Freescale Semiconductor Demonstration Board for Freescale MC9S12XHY256 Microcontroller DEMO9S12XHY256 DEMO9S12XHY256

Freescale Semiconductor

471

The SCI uses the standard NRZ mark/space data format. When Infrared is enabled, the SCI uses RZI data
format where zeroes are represented by light pulses and ones remain low. See

 below.

Each data character is contained in a frame that includes a start bit, eight or nine data bits, and a stop bit.
Clearing the M bit in SCI control register 1 configures the SCI for 8-bit data characters. A frame with eight
data bits has a total of 10 bits. Setting the M bit configures the SCI for nine-bit data characters. A frame
with nine data bits has a total of 11 bits.

When the SCI is configured for 9-bit data characters, the ninth data bit is the T8 bit in SCI data register
high (SCIDRH). It remains unchanged after transmission and can be used repeatedly without rewriting it.
A frame with nine data bits has a total of 11 bits.

1

8

0

0

1

1

7

0

1

1

1

7

1

1

1

The address bit identifies the frame as an address
character. See

.

0

1

1

9

0

0

1

1

8

0

1

1

1

8

1

1

0

1

Bit 5

Start

Bit

Bit 0

Bit 1

Next

STOP

Bit

Start

Bit

8-Bit Data Format

(Bit M in SCICR1 Clear)

Start

Bit

Bit 0

NEXT

STOP

Bit

START

Bit

9-Bit Data Format

(Bit M in SCICR1 Set)

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

Bit 8

Bit 2

Bit 3

Bit 4

Bit 6

Bit 7

POSSIBLE

PARITY

Bit

Possible

Parity

Bit

Standard
SCI Data

Infrared
SCI Data

Standard
SCI Data

Infrared
SCI Data