HD404889_03 Datasheet, PDF (90/197 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip LCD Circuit

HD404889/HD404899/HD404878/HD404868 Series
• Timer mode register B2 (TMB2: $011):
Timer mode register B2 (TMB2) is a 3-bit write-only register, used to select the timer B output mode
and EVNB pin detected edge as shown in figure 40.
Timer mode register B2 (TMB2) is reset to $0 by an MCU reset.
Timer mode register B2 (TMB2: $011)
Bit
3
2
Read/Write

W
Initial value on reset

0
Bit name

TMB22
1
W
0
TMB21
0
W
0
TMB20
TMB21 TMB20 EVNB pin detected edge
0
Not detected
0
1
Falling edge detection
0
Rising edge detection
1
1
Both rising and falling edge detection
TMB22 Timer B output waveform
0
Toggle output
1
PWM output
Figure 40 Timer Mode Register B2 (TMB2)
• Timer write register B (TWBL: $012, TWBU:$013):
Timer write register B (TWBL, TWBU) is a write-only register composed of a lower digit (TWBL) and
an upper digit (TWBU) (figures 41 and 42).
The lower digit (TWBL) of timer write register B is reset to $0 by an MCU reset, while the upper digit
(TWBU) is undetermined.
Timer B can be initialized by writing to timer write register B (TWBL, TWBU). To write the data, first
write the lower digit (TWBL). The lower digit write does not change the timer B value. Next, write the
upper digit (TWBU). Timer B is then initialized to the timer write register B (TWBL, TWBU) value.
When writing to timer write register B (TWBL, TWBU) from the second time onward, if it is not
necessary to change the lower digit (TWBL) reload value, timer B initialization is completed by the
upper digit write alone.
Rev.6.00, Sep.08.2003, page 90 of 197