
R8C/2C Group, R8C/2D Group
Rev.2.00
Dec 05, 2007
REJ09B0339-0200
NOTES:
1. The set value is reflected at the following one-shot pulse after writing to registers TRBSC and
TRBPR.
2. Do not set both the TRBPRE and TRBPR registers to 00h.
Table 14.11
Programmable Wait One-Shot Generation Mode Specifications
Item
Specification
Count sources
f1, f2, f8, timer RA underflow
Count operations
Decrement the timer RB primary setting value.
When a count of the timer RB primary underflows, the timer reloads the
contents of timer RB secondary before the count continues.
When a count of the timer RB secondary underflows, the timer reloads the
contents of timer RB primary before the count completes and the TOSSTF
bit is set to 0 (one-shot stops).
When the count stops, the timer reloads the contents of the reload register
before it stops.
Wait time
(n+1)(m+1)/fi
fi: Count source frequency
n: Value set in the TRBPRE register, m Value set in the TRBPR register
(2)One-shot pulse output time (n+1)(p+1)/fi
fi: Count source frequency
n: Value set in the TRBPRE register, p: Value set in the TRBSC register
Count start conditions
The TSTART bit in the TRBCR register is set to 1 (count starts) and the
next trigger is generated.
Set the TOSST bit in the TRBOCR register to 1 (one-shot starts).
Input trigger to the INT0 pin
Count stop conditions
When reloading completes after timer RB underflows during secondary period.
When the TOSSP bit in the TRBOCR register is set to 1 (one-shot stops).
When the TSTART bit in the TRBCR register is set to 0 (count starts).
When the TSTOP bit in the TRBCR register is set to 1 (count forcibly
stops).
Interrupt request
generation timing
In half a cycle of the count source after timer RB underflows during
secondary period (complete at the same time as waveform output from the
TRBO pin) [timer RB interrupt].
TRBO pin function
Pulse output
INT0 pin functions
When the INOSTG bit in the TRBIOC register is set to 0 (INT0 one-shot
trigger disabled): programmable I/O port or INT0 interrupt input
When the INOSTG bit in the TRBIOC register is set to 1 (INT0 one-shot
trigger enabled): external trigger (INT0 interrupt input)
Read from timer
The count value can be read out by reading registers TRBPR and TRBPRE.
Write to timer
When registers TRBPRE, TRBSC, and TRBPR are written while the count
stops, values are written to both the reload register and counter.
When registers TRBPRE, TRBSC, and TRBPR are written to during count
operation, values are written to the reload registers only.
(1)Select functions
Output level select function
The TOPL bit in the TRBIOC register selects the output level of the one-
shot pulse waveform.
One-shot trigger select function