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TC1796
Peripheral Units (Vol. 2 of 2)
General Purpose Timer Array (GPTA)
User’s Manual
24-101
V2.0, 2007-07
GPTA, V2.0
The GTC input multiplexer contains GTC input Multiplexer Groups (GIMGs) that connect
the I/O groups or Local Timer Cells with the input lines of the GTC input lines, organized
into four GTC groups with 8 cells each. GTC input Multiplexer Group are grouped into
seven IOGs (IOG[6:0]) with eight lines each and eight LTC groups (LTCG[7:0]) with
8 cells each. One special FPC/INT group with eight outputs is established that combines
the six FPC outputs and two internal input lines INT[1:0] as a group of GIMGs inputs.
shows the logical structure of a GIMG.
Figure 24-66 GTC Input Multiplexer Group (GIMG) Structure
Rules for connections to GTC Input Multiplexer Group GIMG:
•
Within a I/O group or LTC group, the line or the output of the cell with the lowest index
number is connected to GIMG input line IN0. The remaining lines, cells or lines of a
group are connected to GIMG input lines IN1 to IN7 with ascending index numbers.
At the FPC/INT group, FPC[5:0] is connected to IN[5:0] and INT[1:0] is connected to
IN[7:6].
Example: for GIMG23 (see
), the cells LTC24 up to LTC31 are wired to
the GIMG23 input lines IN0 to line IN7.
•
Multiplexer output OUT0 is always connected to the input of a GTC group with the
lowest index. The remaining output lines OUT1 to OUT7 are connected to the GTC
inputs with ascending index.
Example: for GIMG23 (see
), the outputs OUT0 to OUT7 are wired to
the inputs of GTC16 to GTC23.
•
A GTC input can be connected either to an I/O group output, or to an LTC output, or
to an FPC/INT output. This is guaranteed by the GIMG control register layout.
Otherwise, short circuits and unpredictable behavior would occur. In contrast, it is
MCA05975
From other GIMGs
IN0
IN1
IN2
IN3
IN4
IN5
IN6
IN7
Outputs of an
I/O Group or
LTC Group or
FPC/INT Group
To other
GIMGs
OU
T
0
OU
T
1
OU
T
2
OU
T
3
OU
T
4
OU
T
5
OU
T
6
OU
T
7
To GTC Groups
More than one switch
might be closed per row,
only one switch can be
closed per column