Chapter 22 Timer Module (TIM16B8CV2) Block Description
MC9S12XE-Family Reference Manual , Rev. 1.19
796
Freescale Semiconductor
Read: Anytime
Write: Anytime
22.3.2.5
Timer Count Register (TCNT)
The 16-bit main timer is an up counter.
A full access for the counter register should take place in one clock cycle. A separate read/write for high
byte and low byte will give a different result than accessing them as a word.
Read: Anytime
Write: Has no meaning or effect in the normal mode; only writable in special modes (test_mode = 1).
The period of the first count after a write to the TCNT registers may be a different size because the write
is not synchronized with the prescaler clock.
Table 22-5. OC7D Field Descriptions
Field
Description
7:0
OC7D[7:0]
Output Compare 7 Data
— A channel 7 output compare can cause bits in the output compare 7 data register
to transfer to the timer port data register depending on the output compare 7 mask register.
Module Base + 0x0004
15
14
13
12
11
10
9
9
R
TCNT15
TCNT14
TCNT13
TCNT12
TCNT11
TCNT10
TCNT9
TCNT8
W
Reset
0
0
0
0
0
0
0
0
Figure 22-10. Timer Count Register High (TCNTH)
Module Base + 0x0005
7
6
5
4
3
2
1
0
R
TCNT7
TCNT6
TCNT5
TCNT4
TCNT3
TCNT2
TCNT1
TCNT0
W
Reset
0
0
0
0
0
0
0
0
Figure 22-11. Timer Count Register Low (TCNTL)
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:
S12XE
products
in
208
MAPBGA
packages
