MC68HC812A4 Datasheet, PDF (249/342 Pages) Motorola, Inc – 16-bit device composed of standard on-chip peripheral modules connected by an intermodule bus. Modules include

Serial Communications Interface Module (SCI)
Register Descriptions and Reset Initialization
14.7.1 SCI Baud Rate Registers
SCI0: $00C0
SCI1: $00C8
Bit 7
6
5
4
3
2
1
Bit 0
Read:
BTST
Write:
BSPL
BRLD SBR12 SBR11 SBR10 SBR9
SBR8
Reset: 0
0
0
0
0
0
0
0
Figure 14-17. SCI Baud Rate Register High (SC0BDH or SC1BDH)
SCI0: $00C1
SCI1: $00C9
Bit 7
6
5
4
3
2
1
Bit 0
Read:
SBR7
Write:
SBR6
SBR5
SBR4
SBR3
SBR2
SBR1
SBR0
Reset: 0
0
0
0
0
1
0
0
Figure 14-18. SCI Baud Rate Register Low (SC0BDL or SC1BDL)
Read: Anytime
Write: SBR[12:0] anytime; BTST, BSPL, and BRLD only in special
modes
BTST — Reserved for test function
BSPL — Reserved for test function
BRLD — Reserved for test function
SBR[12:0] — SCI Baud Rate Bits
The value written to SBR[12:0] determines the baud rate of the SCI.
The new value takes effect when the low order byte is written. The
formula for calculating baud rate is:
SCI baud rate = _{1--M--6----C-×}----LB---K--R---
BR = value written to SBR[12:0], a value from 1 to 8191
NOTE:
The baud rate generator is disabled until the TE bit or the RE bit is set
for the first time after reset. The baud rate generator is disabled when
BR = 0.
Advance Information
MOTOROLA
Serial Communications Interface Module (SCI)
MC68HC812A4 — Rev. 3.0
249