MC68HC708XL36 FREESCALE [Freescale Semiconductor, Inc], MC68HC708XL36 Datasheet - Page 241

• Manufacturer Part Number: MC68HC708XL36
• Description: HCMOS Microcontroller Unit
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Data Format
Transmitter
Character Length
Character
Transmission
7-sci_d
MOTOROLA
The SCI uses the standard non-return-to-zero mark/space data format
illustrated in
Figure 4
The transmitter can accommodate either 8-bit or 9-bit data. The state of
the M bit in SCI control register 1 (SCC1) determines character length.
When transmitting 9-bit data, bit T8 in SCI control register 3 (SCC3) is
the ninth bit (bit 8).
During an SCI transmission, the transmit shift register shifts a character
out to the TxD pin. The SCI data register (SCDR) is the write-only buffer
between the internal data bus and the transmit shift register. To initiate
an SCI transmission:
1. Enable the SCI by writing a logic 1 to the enable SCI bit (ENSCI)
2. Enable the transmitter by writing a logic 1 to the transmitter enable
3. Clear the SCI transmitter empty bit by first reading SCI status
4. Repeat step 3 for each subsequent transmission.
Freescale Semiconductor, Inc.
START
START
BIT
BIT
For More Information On This Product,
in SCI control register 1 (SCC1).
bit (TE) in SCI control register 2 (SCC2).
register 1 (SCS1) and then writing to the SCDR. In a DMA transfer,
the DMA automatically clears the SCTE bit by writing to the
SCDR.
BIT 0
BIT 0
shows the structure of the SCI transmitter.
Go to: www.freescale.com
Figure
BIT 1
BIT 1
BIT 2
BIT 2
3.
Figure 3. SCI Data Formats
SCI
BIT 3
BIT 3
(BIT M IN SCC1 CLEAR)
8-BIT DATA FORMAT
9-BIT DATA FORMAT
(BIT M IN SCC1 SET)
BIT 4
BIT 4
BIT 5
BIT 5
BIT 6
BIT 6
OR DATA
PARITY
BIT 7
BIT 7
BIT
OR DATA
PARITY
STOP
BIT 8
BIT
BIT
Functional Description
START
NEXT
STOP
MC68HC708XL36
BIT
BIT
START
NEXT
BIT
SCI
241