TC1796
Peripheral Units (Vol. 2 of 2)
General Purpose Timer Array (GPTA)
User’s Manual
24-272
V2.0, 2007-07
GPTA, V2.0
24.6.6
Limits of Cascading GTCs and LTCs
As shown on
and
, a maximum of 32 GTCs and a maximum of
64 LTCs can be cascaded. In the TC1796, however cascading of GTCs and LTCs is
limited under certain conditions.
If the LTCs are running with the maximum module timer clock of
f
GPTA
=
f
SYS
= 75 MHz,
a maximum of 20 GTCs and 20 LTCs can be connected together. If the module timer
clock
f
GPTA
is reduced, the number of LTCs that can be cascaded increases accordingly.
Only the integer part of the divider ratio as selected by the GPTA0_FDR fractional divider
register determines the maximum number of cascaded GTCs and LTCs.
Table 24-31 Limits of Cascading GTCs and LTCs
f
SYS
Selected Clock
Divider Ratio
1)
1) Selected by the GPTA0_FDR fractional divider register.
Max. Number of Cascaded GTCs/LTCs
75 MHz
1 <=
f
SYS
/
f
GPTA
< 2
20 GTCs, 20 LTCs
2 <=
f
SYS
/
f
GPTA
< 3
no limits for GTCs, 40 LTCs
3 <=
f
SYS
/
f
GPTA
no limits for GTCs and LTCs