Datasheet

Chapter 14 Serial Communications Interface (S08SCIV3)
MC9S08QG8 and MC9S08QG4 Data Sheet, Rev. 5
Freescale Semiconductor 193
Figure 14-2. SCI Module Quick Start
SBR12 SBR11 SBR10 SBR9 SBR8
SBR4 SBR3 SBR2 SBR1 SBR0SBR7 SBR6 SBR5SCIBDL
SCIBDH
Baud rate = BUSCLK / (16 x SBR12:SBR0)
M WAKE ILT PE PT
SCIC1
LOOPS SCISWAI RSRC
Module configuration
ILIE TE RE RWU SBK
SCIC2
TIE TCIE RIE
Local interrupt enables Tx and Rx enable
Rx wakeup and send break
IDLE OR NF FE PF
SCIS1
TDRE TC RDRF
Interrupt flags Rx error flags
BRK13 RAF
SCIS2
Configure LIN support options and monitor receiver activity
FEIE PEIE
SCIS3
9th data bits
TXDIRR8 T8 ORIE NEIE
SCIID
Read: Rx data; write: Tx data
R5/T5R7/T7 R6/T6
Rx/Tx pin
direction in
Local interrupt enables
R4/T4 R3/T3 R2/T2 R1/T1 R0/T0
TXINV
Tx data path
polarity
single-wire
mode
Module Initialization:
Write: SCIBDH:SCIBDL to set baud rate
Write: SCFC1 to configure 1-wire/2-wire, 9/8-bit data, wakeup, and parity, if used.
Write; SCIC2 to configure interrupts, enable Rx and Tx, RWU
Enable Rx wakeup, SBK sends break character
Write: SCIC3 to enable Rx error interrupt sources. Also controls pin direction in
1-wire modes. R8 and T8 only used in 9-bit data modes.
Module Use:
Wait for TDRE, then write data to SCID
Wait for RDRF, then read data from SCID
A small number of applications will use RWU to manage automatic receiver wakeup, SBK to send break characters, and
R8 and T8 for 9-bit data.