11 PROGRaMMaBle TiMeR
S1C63003/004/008/016 TeChniCal Manual
Seiko epson Corporation
11-11
(Rev. 1.1)
10.2 Selecting count clock frequency
Table 11.
PTPSx[3:0]
Timer clock
FH
f
OSC3
EH
f
OSC3
/ 2
DH
f
OSC3
/ 4
CH
f
OSC3
/ 8
BH
f
OSC3
/ 16
AH
f
OSC3
/ 32
9H
f
OSC3
/ 64
8H
f
OSC3
/ 256
7H
f
OSC1
(32 kHz)
6H
f
OSC1
/ 2 (16 kHz)
5H
f
OSC1
/ 4 (8 kHz)
4H
f
OSC1
/ 16 (2 kHz)
3H
f
OSC1
/ 32 (1 kHz)
2H
f
OSC1
/ 64 (512 Hz)
1H
f
OSC1
/ 256 (128 Hz)
0H
Off
f
OSC1
: OSC1 oscillation frequency. ( ) indicates the frequency when f
OSC1
= 32 kHz.
f
OSC3
: OSC3 oscillation frequency
The clock manager generates the down-count clock for each timer by dividing the OSC1 or OSC3 clock. Table
11.10.2 lists the 15 count clocks that can be generated by the clock manager, and the clock to be used for each
timer can be selected using PTPSx[3:0]. At initial reset, the PTPSx[3:0] register is set to "0H" and the clock sup-
ply from the clock manager to the programmable timer is disabled. Before the timer can be run, select a clock to
enable the clock supply.
Stop the clock supply to the timers shown below by setting PTPSx[3:0] to "0H" to reduce current consumption.
• Unused timer
• Timer used as an event counter that inputs an external clock
• Upper 8-bit timer (Timer 1, Timer 3) when a timer unit is used as 16-bit
×
1 channel configuration.
At initial reset, these registers are set to "0."
The S1C63004/008 does not include a register at FF1BH. The S1C63003 does not include registers at FF19H–
FF1BH.
PlPul_a: Timer 0 pulse polarity select register (FF80h•D0)
PlPul_B: Timer 2 pulse polarity select register (FF90h•D0) – S1C63004/008/016
Selects the count pulse polarity in the event counter mode.
When "1" is written: Rising edge
When "0" is written: Falling edge
Reading: Valid
The count timing in the event counter mode is selected from either the falling edge of the external clock input to
the EVIN_A (P10) and EVIN_B (P22) terminals or the rising edge. When "0" is written to these registers, the
falling edge is selected and when "1" is written, the rising edge is selected. These registers are effective only when
the timer is used in the event counter mode. At initial reset, these registers are set to "0."
The S1C63003 does not include a register at FF90H.
FCSel_a: Timer 0 function select register (FF80h•D1)
FCSel_B: Timer 2 function select register (FF90h•D1) – S1C63004/008/016
Selects whether the noise rejector of the clock input circuit will be used or not in the event counter mode.
When "1" is written: With noise rejector
When "0" is written: Without noise rejector
Reading: Valid
When "1" is written to these registers, the noise rejector is used and counting is done by an external clock (input
from EVIN_A or EVIN_B) with 0.98 msec* or more pulse width. The noise rejector allows the counter to input
the clock at the second falling edge of the internal 2,048 Hz* signal after changing the input level of the I/O port
terminal. Consequently, the pulse width of noise that can reliably be rejected is 0.48 msec* or less.
(
*
: When f
OSC1
= 32.768 kHz)