
13 PWM Timer (T16E)
13-6
EPSON
S1C17003 TECHNICAL MANUAL
13.6 Clock Output Control
The PWM Timer can generate a TOUT3/TOUTN3 signal using the compare match signal.
Figure 13.6.1 shows the PWM Timer clock output circuit.
Logic
Clock
OUTEN
TOUT3 (P36)
TOUTN3 (P37)
INVOUT
D Q
Q
INITOL
Compare A
Compare B
Figure 13.6.1: PWM Timer clock output circuit
Initial output level settings
The default output level is 0 (Low level) while the TOUT3 clock output is Off (TOUTN3 output is High level).
This can be changed to 1 (TOUT3 = High level, TOUTN3 = Low level) with INITOL (D8/T16E_CTL register).
INITOL: Initial Output Level Select Bit in the PWM Timer Ch.x Control (T16E_CTL) Register
(D8/0x5306)
When INITOL is 0 (default), TOUT3 initial output level is low (TOUT3 output is High). When INITOL is set to 1,
the initial output level should be high (TOUT3 output is Low).
Output signal polarity selection
By default, an active High (normal Low) TOUT3 output signal is generated (TOUTN3 output signal is active
Low). This logic can be inverted by INVOUT (D4/T16E_CTL register). Writing 1 to INVOUT causes the timer
to generate an active Low (normal High) TOUT3 signal (TOUTN3 signal is active High).
INVOUT: Inverse Output Control Bit in the PWM Timer Control (T16E_CTL) Register (D4/0x5306)
Setting INVOUT to 1 also inverts the initial output level set for INITOL.
See Figure 13.6.2 for more information on output waveforms.
Output pin settings
The TOUT3/TOUTN3 signal generated here can be output from the following pins and can provide a
programmable clock and PWM signal to external devices.
TOUT3 output
→ TOUT3 (P36) pin, TOUTN3 output → TOUTN3 (P37) pin
The pin used for output is set for input/output port use after initial resetting and switches to input mode. The
pin then becomes high-impedance.
Switching the pin function to TOUT3/TOUTN3 output outputs the level set by INITOL and INVOUT. After the
timer output starts, the output is maintained at this level until changed by the counter value.
Table 13.6.1: Initial output level
INITOL
INVOUT
Initial output level
1
Low
1
0
High
0
1
High
0
Low