Specifications

SCI Module Registers
8-25 Serial Communications Interface (SCI)
8.6.3 Baud-Select Registers
The values in the baud-select registers (SCIHBAUD and SCILBAUD) specify
the baud rate for the SCI.
Figure 8–12. Baud-Select MSbyte Register (SCIHBAUD) — Address 7052h
15 14 13 12 11 10 9 8
BAUD15
(MSB)
BAUD14 BAUD13 BAUD12 BAUD11 BAUD10 BAUD9 BAUD8
RW-0 RW-0 RW-0 RW-0 RS-0 RW-0 RW-0 RW-0
Note: R = Read access, W = Write access, S = Set only, -0 = value after reset
Figure 8–13. Baud-Select LSbyte Register (SCILBAUD) — Address 7053h
76543210
BAUD7
BAUD6 BAUD5 BAUD4 BAUD3 BAUD2 BAUD1
BAUD0
(LSB)
RW-0 RW-0 RW-0 RW-0 RS-0 RW-0 RW-0 RW-0
Note: R = Read access, W = Write access, S = Set only, -0 = value after reset
Bits 15–0 BAUD15–BAUD0. SCI 16-bit baud selection.
Registers SCIHBAUD (MSbyte) and SCILBAUD (LSbyte) concatenate to form
a 16-bit baud value, BRR.
The
internally-generated serial clock is determined by the CLKOUT and the
two baud select registers. The SCI uses the 16-bit value of these registers to
select one of 64K serial clock rates for the communication modes.
The SCI baud rate is calculated using the following equation:
SCI Asynchronous Baud
CLKOUT
(BRR 1) 8
=
×
+
Alternatively,
BRR
CLKOUT
SCI Asynchronous Baud 8
1
=
×
–
Note that the above formulas are applicable only when 1 ≤ BRR ≤ 65535. If
BRR = 0, then
SCI Asynchronous Baud
CLKOUT
16
=
Where: BRR = The 16-bit value (in decimal) in the baud-select registers.