TC1796
Peripheral Units (Vol. 2 of 2)
Synchronous Serial Interface (SSC)
User’s Manual
20-49
V2.0, 2007-07
SSC, V2.1
The following formulas define the frequency of
f
SSC0
or
f
SSC1
:
(20.2)
(20.3)
Note: In SSC Master Mode, the maximum shift clock frequency is
f
SSCx
/2. In SSC Slave
Mode, the maximum shift clock frequency is
f
SSCx
/4.
Combined with the formulas of the baud rate generator (see
fractional divider (see chapter “System Control Unit” of the TC1796 System Units User’s
Manual), the resulting serial data baud rate is defined by:
(20.4)
(20.5)
Note:
and
apply to normal divider mode of the
fractional divider (FDR.DM = 01
B
apply to
fractional divider mode (FDR.DM = 10
B
).
f
SSCx
f
SYS
1
n
---
×
with n = 1024 - FDR.STEP
=
f
SSCx
f
SYS
n
1024
-------------
×
with n = 0-1023
=
Baud rate
SSC
f
SYS
2
BR.BR_VALUE 1
+
(
)
1024 - FDR.STEP
(
)
×
×
-----------------------------------------------------------------------------------------------------------------------------
=
Baud rate
SSC
f
SYS
FDR.STEP
×
2
BR.BR_VALUE 1
+
(
)
1024
×
×
------------------------------------------------------------------------------------- with FDR.STEP = 0-1023
=