Motorola MC68VZ328 用户手册
12-6
MC68VZ328 User’s Manual
Programming Model
12.2
Programming Model
The following sections provide programming information about the settings of the two 16-bit timers in the
GP timers module. Because the two timers are identical, the register description and the associated table
describing the register settings apply to both registers.
GP timers module. Because the two timers are identical, the register description and the associated table
describing the register settings apply to both registers.
12.2.1
Timer Control Registers 1 and 2
Each timer control (TCTLx) register controls the overall operation of its corresponding GP timer. The
settings for the registers are described in Table 12-2. The TCTL registers control the following:
settings for the registers are described in Table 12-2. The TCTL registers control the following:
•
Selecting the free-running or restart mode after a compare event
•
Selecting the capture trigger event
•
Controlling the output compare mode
•
Enabling the compare event interrupt
•
Selecting the prescaler clock source
•
Enabling and disabling the GP Timer
TCTL1
Timer Control Register 1
0x(FF)FFF600
TCTL2
Timer Control Register 2
0x(FF)FFF610
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
BIT
0
FRR
CAP
OM
IRQEN
CLKSOURCE
TEN
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0x0000
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
BIT
0
FRR
CAP
OM
IRQEN
CLKSOURCE
TEN
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0x0000
Table 12-2. Timer Control Register Description
Name Description
Setting
Reserved
Bits 15–9
Bits 15–9
Reserved
These bits are reserved and should be set to 0.
FRR
Bit 8
Bit 8
Free-Running/Restart—This bit controls the
counter mode of operation after a compare
event occurs. In free-running mode, the
counter continues after the compare. In restart
mode, the counter resets to 0x0000 and
resumes counting.
counter mode of operation after a compare
event occurs. In free-running mode, the
counter continues after the compare. In restart
mode, the counter resets to 0x0000 and
resumes counting.
0 = Restart mode (default).
1 = Free-running mode.
1 = Free-running mode.