SAF-C164SM Infineon Technologies, SAF-C164SM Datasheet - Page 244

• Manufacturer Part Number: SAF-C164SM
• Description: 16-Bit CMOS Microcontroller
• Manufacturer: Infineon Technologies

12.5
The serial channel SSC has its own dedicated 16-bit baud rate generator with 16-bit
reload capability. This permits baud rate generation independent from the timers.
The baud rate generator is clocked with the CPU clock divided by 2 (
counts downwards and can be started or stopped through the global enable bit SSCEN
in register SSCCON. Register SSCBR is the dual-function Baud Rate Generator/Reload
register. Reading SSCBR, while the SSC is enabled, returns the contents of the timer.
Reading SSCBR, while the SSC is disabled, returns the programmed reload value. In
this mode, the desired reload value can be written to SSCBR.
Note: Never write to SSCBR while the SSC is enabled.
The formulas below calculate either the resulting baud rate for a given reload value, or
the required reload value for a given baudrate:
<SSCBR> represents the contents of the reload register taken as an unsigned 16-bit
integer.
Table 12-2
the resulting bit times, for different CPU clock frequencies.
Table 12-2
16 MHz
250
375
500
625
1.00
1.25
10
12.5
15.6
20.6
1
User’s Manual
B
SSC
=
2
ns
ns
ns
ns
ms
s
s
s
s
s
s
(<SSCBR> + 1)
Baud Rate Generation
lists some possible baud rates together with the required reload values and
SSC Bit-Time Calculation
f
CPU
20 MHz
200
300
400
500
800
1
8
10
12.5
16.5
800
Reserved. SSCBR must be > 0.
Bit-time for
ns
ns
ns
ns
ns
s
s
s
s
s
s
,
SSCBR =
25 MHz
160
240
320
400
640
800
6.4
8
10
13.2
640
f
CPU
12-13
High-Speed Synchronous Serial Interface
= …
ns
ns
ns
ns
ns
ns
(
s
s
s
s
s
2
Baudrate
f
CPU
33 MHz
121
182
242
303
485
606
4.8
6.1
7.6
10
485
SSC
)
ns
ns
ns
ns
ns
ns
- 1
s
s
s
s
s
C164CM/C164SM
f
CPU
/ 2). The timer
Reload Val.
(SSCBR)
0000
0001
0002
0003
0004
0007
0009
004F
0063
007C
00A4
1F3F
Derivatives
V1.0, 2002-02
H
H
H
H
H
H
H
H
H
H
H
H