MC68HC16Z1 Datasheet, PDF (434/500 Pages) Freescale Semiconductor, Inc – M68HC16Z Series

Freescale Semiconductor, Inc.
SCI Baud Rate = _{3----2-----×}----S----C-f--^s--B-^y--^s-R----[--1---2---:--0----]
or
SCBR[12:0] = _{3----2-----×}----S----C-----I---B----a---u--f--^s_d--^y--^s-R----a---t--e-----D----e----s---i-r--e---d--
where SCBR[12:0] is in the range of one to 8191. Writing a value of zero to SCBR dis-
ables the baud rate generator. There are 8191 different baud rates available. The
baud value depends on the value for SCBR and the system clock, as used in the equa-
tion above. Table D-41 shows possible baud rates for a 16.78-MHz system clock. The
maximum baud rate with this system clock speed is 524 kbaud.
Table D-41 Examples of SCI Baud Rates
Nominal
Baud Rate
500,00.00
38,400.00
32,768.00
19,200.00
9,600.00
4,800.00
2,400.00
1,200.00
600.00
300.00
110.00
64.00
Actual
Baud Rate
524,288.00
37,449.14
32,768.00
19,418.07
9,532.51
4,809.98
2,404.99
1,199.74
599.87
299.94
110.01
64.00
Percent Error Value of SCBR
4.86
–2.48
0.00
1.14
–0.70
0.21
0.21
–0.02
–0.02
–0.02
0.01
0.01
1
14
16
27
55
109
218
437
874
1,748
4,766
8,191
D.7.10 SCI Control Register 1
SCCR1A — SCIA Control Register 1
SCCR1B — SCIB Control Register 1
$YFFC1A
$YFFC2A
15
14
13
12
11
10
NOT
USED
LOOPS WOMS ILT
PT
PE
RESET:
0
0
0
0
0
9
8
7
6
5
4
3
2
1
0
M WAKE TIE TCIE RIE ILIE TE RE RWU SBK
0
0
0
0
0
0
0
0
0
0
SCCR1 contains SCI configuration parameters, including transmitter and receiver en-
able bits, interrupt enable bits, and operating mode enable bits. SCCR0 can be read
or written at any time. The SCI can modify the RWU bit under certain circumstances.
Changing the value of SCCR1 bits during a transfer operation can disrupt the transfer.
D-60
REGISTER SUMMARY
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M68HC16 Z SERIES
USER’S MANUAL