Datasheet
Section 11 16-Bit Timer Pulse Unit (TPU) 
R01UH0310EJ0500 Rev. 5.00    Page 721 of 1384 
Sep 25, 2012     
H8S/2426, H8S/2426R, H8S/2424 Group 
11.3.2  Timer Mode Register (TMDR) 
TMDR registers are used to set the operating mode for each channel. The TPU has six TMDR 
registers, one for each channel. TMDR register settings should be made only when TCNT 
operation is stopped. 
Bit  Bit Name  Initial Value  R/W  Description 
7 
6 
⎯ 
⎯ 
1 
1 
⎯ 
⎯ 
Reserved 
These bits are always read as 1 and cannot be 
modified. 
5  BFB  0  R/W  Buffer Operation B  
Specifies whether TGRB is to operate in the 
normal way, or TGRB and TGRD are to be used 
together for buffer operation. When TGRD is used 
as a buffer register, TGRD input capture/output 
compare is not generated. 
In channels 1, 2, 4, and 5, which have no TGRD, 
bit 5 is reserved. It is always read as 0 and cannot 
be modified. 
0: TGRB operates normally 
1: TGRB and TGRD used together for buffer 
operation 
4  BFA  0  R/W  Buffer Operation A 
Specifies whether TGRA is to operate in the 
normal way, or TGRA and TGRC are to be used 
together for buffer operation. When TGRC is used 
as a buffer register, TGRC input capture/output 
compare is not generated. 
In channels 1, 2, 4, and 5, which have no TGRC, 
bit 4 is reserved. It is always read as 0 and cannot 
be modified. 
0: TGRA operates normally 
1: TGRA and TGRC used together for buffer 
operation 
3 
2 
1 
0 
MD3 
MD2 
MD1 
MD0 
0 
0 
0 
0 
R/W 
R/W 
R/W 
R/W 
Modes 3 to 0 
These bits are used to set the timer operating 
mode. 
MD3 is a reserved bit. The write value should 
always be 0. See table 11.12 for details. 










