TC1784
System Control Unit (SCU)
User´s Manual
3-54
V1.1, 2011-05
32-bit SCU, V1.18
Fractional Divider Operation
The fractional divider divides the input clock
f
CLC
either by the factor 1/n or by a fraction
of n/1024 for any value of n from 0 to 1023, and outputs the clock signal,
f
MOD
. The
fractional divider is controlled by the MOD_FDR register.
The fractional divider can be configured for two operating modes:
•
Normal Divider Mode:
Reload counter (RESULT = 1), generating an
output clock pulse on counter overflow.
•
Fractional Divider Mode:
Add a STEP value to the RESULT value and generates
an output clock pulse on counter overflow.
Normal Divider Mode
In Normal Divider Mode (MOD_FDR.DM = 01
B
), the fractional divider behaves as a
reload counter (addition of +1) that generates an output clock pulse at
f
MOD
on the
transition from 3FF
H
to 000
H
. MOD_FDR.RESULT represents the counter value and
MOD_FDR.STEP determines the reload value.
The output frequencies in Normal Divider Mode are defined according to the following
formulas:
, with n = 1024 - STEP
(3.17)
Note: Each write to register FDR with bit field DM = 01
B
or 10
B
sets bit field RESULT to
3FF
H
.
In order to get
f
MOD
=
f
CLC
MOD_FDR.STEP must be programmed with 3FF
H
.
shows the operation of the Normal Divider Mode with a reload value of
MOD_FDR.STEP = 3FD
H
.
Figure 3-17 Normal Divider Mode
f
MOD
f
CL C
1
n
---
×
=
MCT05605_m
RESULT
3FF
f
CLC
3FE
3FD
3FF
3FD
3FD
3FE
3FF
3FD
3FE
STEP
Reload
3FD
Reload
3FD
Reload
f
MOD
Содержание TC1784
Страница 1: ...User s Manual V1 1 2011 05 Microcontrollers TC1784 32 Bit Single Chip Microcontroller ...
Страница 3: ...User s Manual V1 1 2011 05 Microcontrollers TC1784 32 Bit Single Chip Microcontroller ...
Страница 950: ...TC1784 Direct Memory Access Controller DMA User s Manual 11 132 V1 1 2011 05 DMA V3 03 ...
Страница 1949: ...TC1784 General Purpose Timer Array GPTA v5 User s Manual 21 297 V1 1 2011 05 GPTA v5 V1 14 ...
Страница 2350: ...w w w i n f i n e o n c o m Published by Infineon Technologies AG Doc_Number ...