7220 Datasheet, PDF (63/303 Pages) Renesas Technology Corp – 8-BIT SINGLE-CHIP MICROCOMPUTER

FUNCTIONAL DESCRIPTION
2.6 Timers
Timer 12 Mode Register
b7 b6 b5 b4 b3 b2 b1 b0
0
Timer 12 mode register (T12M) [Address 00F416]
B
Name
0 Timer 1 count source
selection bit (T12M0)
Functions
0: f(XIN)/16
1: f(XIN)/4096
1 Timer 2 count source
selection bit
(T12M1)
2 Timer 1 count
stop bit (T12M2)
3 ^{Timer 2 count stop}
bit (T12M3)
4 Timer 2 internal count
source selection bit
(T12M4)
5 Fix this bit to “0.”
0: Internal clock
1: External clock from
P24/TIM2 pin
0: Count start
1: Count stop
0: Count start
1: Count stop
0: f(XIN)/16
1: Timer 1 overflow
6,7 Nothing is assigned. These bits are write disable
bits. When these bits are read out, the values are
“0.”
After reset R W
0 RW
0 RW
0 RW
0 RW
0 RW
0 RW
0 R—
Fig. 2.6.3 Timer 12 mode register (address 00F416)
(3) Timer 3
Timer 3 can select one of the following count sources:
q f(XIN)/16
q External clock from pin HSYNC
q External clock from pin P23/TIM3
The count source of timer 3 is selected by setting bits 5 and 0 of the timer 34 mode register (address
00F516)
Timer 3 interrupt request occurs at timer 3 overflow.
(4) Timer 4
Timer 4 can select one of the following count sources:
q f(XIN)/16
q f(XIN)/2
q Timer 3 overflow signal
The count source of timer 3 is selected by setting bits 4 and 1 of the timer 34 mode register (address
00F516). When timer 3 overflow signal is a count source for timer 4, timer 3 functions as an 8-bit
prescaler.
Timer 4 interrupt request occurs at timer 4 overflow.
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7220 Group User’s Manual