TC1796
Peripheral Units (Vol. 2 of 2)
General Purpose Timer Array (GPTA)
User’s Manual
24-223
V2.0, 2007-07
GPTA, V2.0
The output multiplexer logic as seen for programming is shown in
this logic, three GTC or LTC group signals are always combined to one output line that
leads to the input of an I/O or output group. For example, when looking at
each of the eight output multiplexer output lines to I/O group IOG4 is connected via two
OMGn4 (n = 1, 2) with the eight outputs of two LTC groups (LTCG0 and LTCG4).
Figure 24-79 OMG Multiplexer (Programmer’s View)
The 1. level multiplexer is built up by two 8:1 multiplexers that are controlled in parallel
by bit field OMLn. Bit field OMGn controls the 2. level multiplexer and connects one of
the 1. level multiplexer outputs to output n. The output of the 2. level multiplexer is only
connected only to the input of an I/O group or output group if bit MRACTL.MAEN
(multiplexer array enabled) is set. If MRACTL.MAEN = 0, the corresponding OMG output
will be held at a low level.
Two Output Multiplexer Control Registers, OMCRL and OMCRH (see also
), are assigned to each of the I/O or output groups. Therefore, in total
24 registers control the connections within the output multiplexer of the LTCA2 module.
The OMCRL registers control the OMG output lines 0 to 3 and the OMCRH registers
control the OMG output lines 4 to 7.
lists all Output Multiplexer Control
Registers with its control functions. Please note that all Output Multiplexer Control
Registers are not directly accessible but must be written or read using the FIFO array
structure as described on
MCA05988
MUX
GTC Group
(OMG1g)
MU
X
LTC Group
(OMG2g)
MU
X
XX0
XX1
2. Level
Mux
OMLn
OMGn
1. Level
Mux
OMCRLg
OMCRHg
(g = 0-13)
To Input of
I/O Group g or
Output Group (g-7)
0
MU
X
0
1
MAEN
MRACTL
8
3
3
8