General Purpose Timer Module (GPT)
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
23-14
Freescale Semiconductor
23.6.16 Pulse Accumulator Flag Register (GPTPAFLG)
4
PEDGE
Pulse accumulator edge. Selects falling or rising edges on the PAI pin to increment the counter.
In event counter mode (PAMOD = 0):
1 Rising PAI edge increments counter
0 Falling PAI edge increments counter
In gated time accumulation mode (PAMOD = 1):
1 Low PAI input enables divide-by-64 clock to pulse accumulator and trailing rising edge on PAI sets PAIF flag.
0 High PAI input enables divide-by-64 clock to pulse accumulator and trailing falling edge on PAI sets PAIF flag.
Note: The timer prescaler generates the divide-by-64 clock. If the timer is not active, there is no divide-by-64 clock.
To operate in gated time accumulation mode:
1. Apply logic 0 to RSTI pin.
2. Initialize registers for pulse accumulator mode test.
3. Apply appropriate level to PAI pin.
4. Enable GPT.
3–2
CLK
Select the GPT counter input clock. Changing the CLK bits causes an immediate change in the GPT counter clock
input.
00 GPT prescaler clock (When PAE = 0, the GPT prescaler clock is always the GPT counter clock.)
01 PACLK
10 PACLK/256
11 PACLK/65536
1
PAOVI
Pulse accumulator overflow interrupt enable. Enables the PAOVF flag to generate interrupt requests.
1 PAOVF interrupt requests enabled
0 PAOVF interrupt requests disabled
0
PAI
Pulse accumulator input interrupt enable. Enables the PAIF flag to generate interrupt requests.
1 PAIF interrupt requests enabled
0 PAIF interrupt requests disabled
IPSBAR
Offset: 0x1A_0019 (GPTPAFLG)
Access: Supervisor read/write
7
6
5
4
3
2
1
0
R
0
0
0
0
0
0
PAOVF
PAIF
W
Reset:
0
0
0
0
0
0
0
0
Figure 23-18. Pulse Accumulator Flag Register (GPTPAFLG)
Table 23-19. GPTPAFLG Field Descriptions
Field
Description
7–2
Reserved, should be cleared.
Table 23-18. GPTPACTL 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
