REGISTER SUMMARY
M68HC16 Z SERIES
D-60
USER’S MANUAL
or
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.
shows possible baud rates for a 16.78-MHz system clock. The
maximum baud rate with this system clock speed is 524 kbaud.
D.7.10 SCI Control Register 1
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.
Table D-41 Examples of SCI Baud Rates
Nominal
Baud Rate
Actual
Baud Rate
Percent Error
Value of SCBR
500,00.00
524,288.00
4.86
1
38,400.00
37,449.14
–2.48
14
32,768.00
32,768.00
0.00
16
19,200.00
19,418.07
1.14
27
9,600.00
9,532.51
–0.70
55
4,800.00
4,809.98
0.21
109
2,400.00
2,404.99
0.21
218
1,200.00
1,199.74
–0.02
437
600.00
599.87
–0.02
874
300.00
299.94
–0.02
1,748
110.00
110.01
0.01
4,766
64.00
64.00
0.01
8,191
SCCR1A — SCIA Control Register 1
$YFFC1A
SCCR1B — SCIB Control Register 1
$YFFC2A
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
NOT
USED
LOOPS
WOMS
ILT
PT
PE
M
WAKE
TIE
TCIE
RIE
ILIE
TE
RE
RWU
SBK
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
SCI Baud Rate
f
sys
32
SCBR[12:0]
×
--------------------------------------------
=
SCBR[12:0]
f
sys
32
SCI Baud Rate Desired
×
---------------------------------------------------------------------------
=
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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