LAPIS Semiconductor ML610471, User Manual, Page: 130 / 281

ML610471/472/473/Q471/Q472/Q473 User's Manual
Chapter 9 Timer
9-16
9.4 Operating Timers by External Clock Inputs
When the external clock is selected as the operation clock for the Timer 2 (8-bit timer mode), operate it by inputting the
clock from the P44 set to the 1st function. When the external clock is selected as the operation clock for the Timer 3
(8-bit timer mode), operate it by inputting the clock with the P45 set to the 1st function.
When the external clock is selected as the operation clock for the Timers 2 and 3 set to the 16-bit timer mode, operate
them by inputting the clock with the P44 set to the 1st function.
Set the external clock frequency to a value below the operating frequency (fop) in "Appendix C Electrical
Characteristics."
9.4.1 Operating Timer 2 (8-Bit Timer Mode) by External Clock (P44/T2CK)
Set the P44MD1 bit (P4MOD1 register's bit 4) to "0" and the P44MD0 bit (P4MOD0 register's bit 4) to "0" for
specifying the P44 to the 1st function.
Register
name
P4MOD1 register (Address: 0F225H)
Bit 7 6 5 4 3 2 1 0
Bit name
P47MD1 P46MD1 P45MD1 P44MD1 P43MD1 P42MD1 - -
Setting
value
* * * 0 * * - -
Register
name
P4MOD0 register (Address: 0F224H)
Bit 7 6 5 4 3 2 1 0
Bit name
P47MD0 P46MD0 P45MD0 P44MD0 P43MD0 P42MD0 - -
Setting
value
* * * 0 * * - -
Set the P44DIR bit (P4DIR register's bit 4) to "1" for specifying the state mode of the P44 pin to input.
Register
name
P4DIR register (Address: 0F221H)
Bit 7 6 5 4 3 2 1 0
Bit name
P47DIR P46DIR P45DIR P44DIR P43DIR P42DIR - -
Setting
value
* * * 1 * * - -
Select the external clock(P44/T2CK) and timer2 (8-bit mode) in the TM2CON0 register, and input the operation clock
for the Timer 2 from the P44 pin.