MC9S12G FREESCALE [Freescale Semiconductor, Inc], MC9S12G Datasheet - Page 584

• Manufacturer Part Number: MC9S12G
• Description: Ignores external trigger. Performs one conversion sequence and stops.
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Serial Communication Interface (S12SCIV5)
18.4.5
18.4.5.1
The SCI transmitter can accommodate either 8-bit or 9-bit data characters. The state of the M bit in SCI
control register 1 (SCICR1) determines the length of data characters. When transmitting 9-bit data, bit T8
in SCI data register high (SCIDRH) is the ninth bit (bit 8).
18.4.5.2
To transmit data, the MCU writes the data bits to the SCI data registers (SCIDRH/SCIDRL), which in turn
are transferred to the transmitter shift register. The transmit shift register then shifts a frame out through
the TXD pin, after it has prefaced them with a start bit and appended them with a stop bit. The SCI data
registers (SCIDRH and SCIDRL) are the write-only buffers between the internal data bus and the transmit
shift register.
584
TDRE IRQ
BER IRQ
TC IRQ
This document is valid for the S12G96 and the S12G128 device. All information related to other devices is preliminary.
Clock
Bus
SBR12:SBR0
Transmitter
Transmitter Character Length
Character Transmission
Baud Divider
PE
PT
M
Generation
Parity
÷ 16
T8
Figure 18-16. Transmitter Block Diagram
MC9S12G Family Reference Manual,
BERRIF
TDRE
TCIE
TCIE
TIE
TC
H
8
7
11-Bit Transmit Register
6
5
SCI Data Registers
Internal Bus
4
Transmitter Control
TE
3
2
Collision Detect
SBK
1
Transmit
Rev.1.01
0
BERRM[1:0]
L
CONTROL
TXPOL
LOOP
Freescale Semiconductor
SCTXD
SCRXD
(From Receiver)
LOOPS
RSRC
To Receiver
SCTXD