HD64F7051SFJ20V Datasheet, PDF (312/843 Pages) Renesas Technology Corp – Hardware Manual Renesas 32-Bit RISC

Section 10 Advanced Timer Unit (ATU)
H'FFFF
Data B
Data A
H'0000
Write to DCNT10A
and DST10A by
user program
Down-count value
DCNT10A
(Data A) DST10A= ‘1’
(Data B)
Time
DST10A = ‘1’
DST10A
TOA10
One-shot
pulse
Automatically
cleared to 0
One-shot pulse
Figure 10.15 Example of One-Shot Pulse Operation
10.3.6 Offset One-Shot Pulse Function
The ATU channel 10 down-counters (DCNT) can be coupled with compare-matches between the
channel 1 and 2 free-running counters (TCNT) and general registers (GR) by setting bits CN10A
to CN10H to 1 in the timer connection register (TCNR). At the same time, the external pins
(TOA10 to TOH10) corresponding to the eight channel 10 down-counters, DCNT10A to
DCNT10H, can be used as offset one-shot pulse output pins.
Setting 1 in timer start register (TSTR) bit STR1 or STR2 starts the up-count by TCNT1 or
TCNT2 in channel 1 or 2. When TCNT1 or TCNT2 matches the general register (GR!A to GR1F,
GR2A, GR2B) value, the down-count start register (DSTR) bit corresponding to bit CN10A to
CN10H in TCNR corresponding to GR automatically changes to 1, and the down-count is started.
When the down-count starts, 1 is output to the corresponding external pin (TOA10 to TOH10). If
the DCNT value is 0, however, the external pin remains at 0 even if DST is set to 1; in this case, a
one-shot pulse is not generated, but an interrupt is requested. When the DCNT value underflows,
DCNT and the relevant DST bit are automatically cleared to 0, and DCNT stops counting. At the
same time, 0 is output to the corresponding external pin. As long as a count value is set in DCNT
Rev. 5.00 Jan 06, 2006 page 290 of 818
REJ09B0273-0500