General Purpose Timer Module (GPT)
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
23-15
NOTE
When the fast flag clear all enable bit (GPTSCR1[TFFCA]) is set, any
access to the pulse accumulator counter registers clears all the flags in
GPTPAFLG.
23.6.17 Pulse Accumulator Counter Register (GPTPACNT)
1
PAOVF
Pulse accumulator overflow flag. Set when the 16-bit pulse accumulator rolls over from 0xFFFF to 0x0000. If the
GPTPACTL[PAOVI] bit is also set, PAOVF generates an interrupt request. Clear PAOVF by writing a 1 to it. This bit
is read anytime, write anytime. (Writing 1 clears the flag; writing 0 has no effect.)
1 Pulse accumulator overflow
0 No pulse accumulator overflow
0
PAIF
Pulse accumulator input flag. Set when the selected edge is detected at the PAI pin. In event counter mode, the event
edge sets PAIF. In gated time accumulation mode, the trailing edge of the gate signal at the PAI pin sets PAIF. If the
PAI bit in GPTPACTL is also set, PAIF generates an interrupt request. Clear PAIF by writing a 1 to it.
1 Active PAI input
0 No active PAI input
IPSBAR
Offset: 0x1A_001A (GPTPACNT)
Access: Supervisor
read/write
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
R
PACNT
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 23-19. Pulse Accumulator Counter Register (GPTPACNT)
Table 23-20. GPTPACR Field Descriptions
Field
Description
15–0
PACNT
Contains the number of active input edges on the PAI pin since the last reset.
Note: Reading the pulse accumulator counter registers immediately after an active edge on the PAI pin may miss
the last count because the input first has to be synchronized with the bus clock.
To ensure coherent reading of the PA counter so that the counter does not increment between back-to-back 8-bit
reads, it is recommended that only word (16-bit) accesses be used. These bits are read anytime, write anytime.
Table 23-19. GPTPAFLG Field Descriptions (continued)
Field
Description
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60
