10 Fine MODe 8-BiT TiMeRS (T8F)
10-8
Seiko epson Corporation
S1C17624/604/622/602/621 TeChniCal Manual
Count clock
Underflow signal (not corrected)
Underflow signal (corrected)
Output clock (not corrected)
Output clock (corrected)
Delayed
15
16
15
16
1
1
10.1 Delay Cycle Insertion in Fine Mode
Figure 10.
D[7:5]
Reserved
D4
TRMD: Count Mode Select Bit
Selects the count mode.
1 (R/W): One-shot mode
0 (R/W): Repeat mode (default)
Setting TRMD to 0 sets the timer to repeat mode. In this mode, once the count starts, the timer contin-
ues to run until stopped by the application program. When the counter underflows, the timer presets the
counter to the reload data register value and continues the count. Thus, the timer periodically outputs an
underflow pulse. Set the timer to this mode to generate periodic interrupts or to generate a serial trans-
fer clock.
Setting TRMD to 1 sets the timer to one-shot mode. In this mode, the fine mode 8-bit timer stops auto-
matically as soon as the counter underflows. This means only one interrupt can be generated after the
timer starts. Note that the timer presets the counter to the reload data register value, then stops when an
underflow occurs. Set the timer to this mode to set a specific wait time.
D[3:2]
Reserved
D1
PReSeR: Timer Reset Bit
Resets the timer.
1 (W):
Reset
0 (W):
Ignored
0 (R):
Always 0 when read (default)
Writing 1 to this bit presets the counter to the reload data value.
D0
PRun: Timer Run/Stop Control Bit
Controls the timer RUN/STOP.
1 (R/W): Run
0 (R/W): Stop (default)
The timer starts counting when PRUN is written as 1 and stops when written as 0. When the timer is
stopped, the counter data is retained until reset or until the next RUN state.
T8F Ch.
x
interrupt Control Registers (T8F_inT
x
)
Register name address
Bit
name
Function
Setting
init. R/W
Remarks
T8F Ch.
x
inter-
rupt Control
Register
(T8F_inT
x
)
0x4208
0x4288
(16 bits)
D15–9 –
reserved
–
–
–
0 when being read.
D8
T8Fie
T8F interrupt enable
1 Enable
0 Disable
0
R/W
D7–1 –
reserved
–
–
–
0 when being read.
D0
T8FiF
T8F interrupt flag
1 Cause of
interrupt
occurred
0 Cause of
interrupt not
occurred
0
R/W Reset by writing 1.
D[15:9] Reserved
D8
T8Fie: T8F interrupt enable Bit
Enables or disables interrupts caused by counter underflows for each channel.
1 (R/W): Interrupt enabled
0 (R/W): Interrupt disabled (default)
Setting T8FIE to 1 enables T8F interrupt requests to the ITC; setting to 0 disables interrupts.