TC1796
Peripheral Units (Vol. 2 of 2)
General Purpose Timer Array (GPTA)
User’s Manual
24-80
V2.0, 2007-07
GPTA, V2.0
The LTC63 provides the following output signals:
•
One data output line (LTCkOUT) that can be connected to:
– External port lines
– Inputs of an MSC module
– Outputs and/or inputs of Global Timer Cell inputs
•
One service request line (SQT) triggered by a compare or copy event
•
An EO output reporting the occurrence of a local event to the adjacent LTC with lower
order number
Figure 24-54 Architecture of Local Timer Cell 63
Compare
The compare function is always enabled. As long as the 16-bit compare value
LTCXR63.X is greater than the timer value provided at YI, the comparator output signal
is 1. The timer value at YI comes from the LTC62 either in original or in reversed order
(Bit0 <-> Bit15, Bit1 <-> Bit14, etc.). The greater comparator output is connected directly
to the output line LTC63OUT.
The 16-bit compare value LTCXR63.X is never greater than the LTC timer value (FFFF
H
)
coming from YI and which is used on LTC timer reset. Without special measures, a duty
cycle of 100% cannot be achieved. There is always one LTC timer clock missing.
Therefore, additional logic generates a permanent high signal whenever the 16-bit
compare value LTCXR63.X is FFFF
H
.
MCA05963
LTC63
Control
Logic
LTC63IN
X (16-Bit Compare)
LTCXR63
LTC63OUT
SQT63
From/To LTC62
EO
TI
YI
>
LTCXR63
MUX
Bit Reversal Logic
XS (16-Bit Shadow)