Datasheet

Section 14 Timer RB
REJ09B0465-0300 Rev. 3.00 Page 427 of 982
Sep 17, 2010
H8S/20103, H8S/20203, H8S/20223, H8S/20115, H8S/20215, H8S/20235 Group
14.2.6 Timer RB Prescaler Register (TRBPRE)
b7
1
b6
1
b5
1
b4
1
b3
1
b2
1
b1
1
b0
1
H'FFFFA4
Bit:
Address:
Value after reset:
TRBPRE is a reload register for the timer RB prescaler. The timer RB prescaler consists of a
reload register and an 8-bit counter.
If a down-count is performed using the count source selected on TRBMR and an underflow
occurs, the value of the reload register is loaded to the counter. The underflow becomes a count
source for TRBTR.
TRBPRE and the counter are assigned to the same address. On write, a value is written to the
reload register, and on read, a counter value is read. During a write to TRBPRE, the load timing
from the reload register to the counter differs between counting in progress and counting stopped
by the setting of the TWRC bit in TRBMR. For details, see descriptions of each operating mode.
The initial values of TRBPRE and the counter are H'FF.
14.2.7 Timer RB Secondary Register (TRBSC)
b7
1
b6
1
b5
1
b4
1
b3
1
b2
1
b1
1
b0
1
H'FFFFA5
Bit:
Address:
Value after reset:
TRBSC is an 8-bit write-only register that sets the secondary period for the timer RB counter. This
register is used only in programmable waveform generation mode and programmable wait one-
shot generation mode. This register is not used in timer mode or programmable one-shot
generation mode.
When TRBSC is written to in any operating mode where TRBSC is used, both the TRBSC and
TRBPR should be written to in this order. Even if only TRBSC is to be modified, TRBPR should
also be set to the previous value. The initial value is H'FF.