Datasheet
Section 11 16-Bit Timer Pulse Unit (TPU) 
Rev. 6.00 Mar. 18, 2010 Page 440 of 982 
REJ09B0054-0600 
11.10.12  Contention between TCNT Write and Overflow/Underflow 
If there is an up-count or down-count in the T
2
 state of a TCNT write cycle, when 
overflow/underflow occurs, the TCNT write takes precedence and the TCFV/TCFU flag in TSR is 
not set. 
Figure 11.54 shows the operation timing when there is contention between TCNT write and 
overflow. 
Write signal
Address
φ
TCNT address
TCNT
TCNT write cycle
T
1
T
2
H'FFFF M
TCNT write data
TCFV flag
Prohibited
Figure 11.54 Contention between TCNT Write and Overflow 
11.10.13  Multiplexing of I/O Pins 
In this LSI, the TCLKA input pin is multiplexed with the TIOCC0 I/O pin, the TCLKB input pin 
with the TIOCD0 I/O pin, the TCLKC input pin with the TIOCB1 I/O pin, and the TCLKD input 
pin with the TIOCB2 I/O pin. When an external clock is input, compare match output should not 
be performed from a multiplexed pin. 
11.10.14 Interrupts and Module Stop Mode 
If module stop mode is entered when an interrupt has been requested, it will not be possible to 
clear the CPU interrupt source or the DMAC* or DTC activation source. Interrupts should 
therefore be disabled before entering module stop mode. 
Note:  *  Supported only by the H8S/2239 Group. 










