TMP86P203PG Datasheet, PDF (71/108 Pages) Toshiba Semiconductor – 8 Bit Microcontroller

TMP86P203PG
8.3.2 8-Bit Event Counter Mode (TC3, 4)
In the 8-bit event counter mode, the up-counter counts up at the falling edge of the input pulse to the TCj pin.
When a match between the up-counter and the TTREGj value is detected, an INTTCj interrupt is generated and
the up-counter is cleared. After being cleared, the up-counter restarts counting at the falling edge of the input
pulse to the TCj pin. Two machine cycles are required for the low- or high-level pulse input to the TCj pin.
Therefore, a maximum frequency to be supplied is fc/2⁴ Hz in the NORMAL1 or IDLE1 mode.
Note 1: In the event counter mode, fix TCjCR<TFFj> to 0. If not fixed, the PDOj, PWMj and PPGj pins may output
pulses.
Note 2: In the event counter mode, do not change the TTREGj setting while the timer is running. Since TTREGj is
not in the shift register configuration in the event counter mode, the new value programmed in TTREGj is in
effect immediately after the programming. Therefore, if TTREGi is changed while the timer is running, an
expected operation may not be obtained.
Note 3: j = 3, 4
TC4CR<TC4S>
TC4 pin input
Counter
0
1
2
n-1 n 0 1 2
n-1 n 0 1 2
0
TTREG4
?
n
INTTC4 interrupt request
Match detect
Counter
clear Match detect
Counter
clear
Figure 8-3 8-Bit Event Counter Mode Timing Chart (TC4)
8.3.3 8-Bit Programmable Divider Output (PDO) Mode (TC3, 4)
This mode is used to generate a pulse with a 50% duty cycle from the PDOj pin.
In the PDO mode, the up-counter counts up using the internal clock. When a match between the up-counter
and the TTREGj value is detected, the logic level output from the PDOj pin is switched to the opposite state and
the up-counter is cleared. The INTTCj interrupt request is generated at the time. The logic state opposite to the
timer F/Fj logic level is output from the PDOj pin. An arbitrary value can be set to the timer F/Fj by
TCjCR<TFFj>. Upon reset, the timer F/Fj value is initialized to 0.
To use the programmable divider output, set the output latch of the I/O port to 1.
Example :Generating 160 Hz pulse using TC4 (fc = 2.5 MHz)
Setting port
LD
(TTREG4), 3DH
LD
(TC4CR), 00010001B
LD
(TC4CR), 00011001B
: 1/160÷2⁷/fc÷2 = 3DH
: Sets the operating clock to fc/2⁷, and 8-bit PDO mode.
: Starts TC4.
Note 1: In the programmable divider output mode, do not change the TTREGj setting while the timer is running.
Since TTREGj is not in the shift register configuration in the programmable divider output mode, the new
value programmed in TTREGj is in effect immediately after programming. Therefore, if TTREGi is changed
while the timer is running, an expected operation may not be obtained.
Note 2: When the timer is stopped during PDO output, the PDOj pin holds the output status when the timer is
stopped. To change the output status, program TCjCR<TFFj> after the timer is stopped. Do not change the
TCjCR<TFFj> setting upon stopping of the timer.
Example: Fixing the PDOj pin to the high level when the TimerCounter is stopped
CLR (TCjCR).3: Stops the timer.
CLR (TCjCR).7: Sets the PDOj pin to the high level.
Note 3: j = 3, 4
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