tmp88cu74 TOSHIBA Semiconductor CORPORATION, tmp88cu74 Datasheet - Page 66

• Manufacturer Part Number: tmp88cu74
• Description: Cmos 8-bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

(5) Pulse width measurement mode
Note: The first captured value after the timer starts may be read incorrectively, therefore, ignore the
The trigger can be selected either the rising or falling edge of the TC1 pin input. The
source clock is used an internal clock. On the next falling (rising) edge, the counter
contents are transferred to TREG1B and an INTTC1 interrupt is generated. The
counter is cleared when the single edge capture mode is set. When double edge capture
is set, the counter continues and, at the next rising (falling) edge, the counter contents
are again transferred to TREG1B. If a falling (rising) edge capture value is required, it
is necessary to read out TREG1B contents until a rising (falling) edge is detected.
Falling or rising edge is selected with INT3ES, and single edge or double edge is
selected with MCAP1 (bit 6 in TC1CR).
first captured value.
Counting is started by the external trigger (set to external trigger start by TC1S).
Example: Duty measurement (resolution fc/2
PINTTC1:
SINTTC1:
VINTTC1:
TC1 pin
INTTC1SW
CLR
LD
LD
SET
EI
LD
CPL
JRS
LD
LD
RETI
LD
LD
RETI
DW
HPULSE
(INTTC1SW). 0
(EINTCR), 00000000B
(TC1CR), 00000110B
(EIRL). EF4
(TC1CR), 00110110B
(INTTC1SW). 0
F, SINTTC1
(HPULSE), (TREG1BL)
(HPULSE + 1), (TREG1BH)
(WIDTH), (TREG1BL)
(WIDTH + 1), (TREG1BH)
PINTTC1
88CU74-66
7
[Hz] DV1CK = 0)
WIDTH
;
;
;
;
;
;
;
;
;
INTTC1 service switch initial setting
Sets the rise edge at the INT3 edge
Sets the TC1 mode and source clock
Enables INTTC1
Starts TC1 with an external trigger at
MCAP1=0
Complements INTTC1 service switch
Reads TREG1B (
Duty calculation
Reads TREG1B (Period)
“H”
level pulse width)
TMP88CU74
2007-10-19