4518 Datasheet, PDF (34/160 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4518 Group
Table 10 Timer related registers
Timer control register PA
PA0 Prescaler control bit
at reset : 02
0
Stop (state initialized)
1
Operating
at RAM back-up : 02
W
TPAA
W13
W12
W11
W10
Timer control register W1
Timer 1 count auto-stop circuit selection
bit (Note 2)
Timer 1 control bit
Timer 1 count source selection bits
at reset : 00002
at RAM back-up : state retained
0 Timer 1 count auto-stop circuit not selected
1 Timer 1 count auto-stop circuit selected
0 Stop (state retained)
1 Operating
W11 W10
Count source
0 0 Instruction clock (INSTCK)
0 1 Prescaler output (ORCLK)
1 0 XIN input
1 1 CNTR0 input
R/W
TAW1/TW1A
W23
Timer control register W2
CNTR0 output signal selection bit
W22 Timer 2 control bit
W21
W20
Timer 2 count source selection bits
at reset : 00002
at RAM back-up : state retained
0 Timer 1 underflow signal divided by 2 output
1 Timer 2 underflow signal divided by 2 output
0 Stop (state retained)
1 Operating
W21 W20
Count source
0 0 System clock (STCK)
0 1 Prescaler output (ORCLK)
1 0 Timer 1 underflow signal (T1UDF)
1 1 PWM signal (PWMOUT)
R/W
TAW2/TW2A
Timer control register W3
at reset : 00002
at RAM back-up : state retained
W33 ^{Timer 3 count auto-stop circuit selection}
bit (Note 3)
0 Timer 3 count auto-stop circuit not selected
1 Timer 3 count auto-stop circuit selected
W32 _{Timer 3 control bit}
0 Stop (state retained)
1 Operating
W31
Timer 3 count source selection bits
W31 W30
Count source
0 0 PWM signal (PWMOUT)
0 1 Prescaler output (ORCLK)
W30
1 0 Timer 2 underflow signal (T2UDF)
1 1 CNTR1 input
Notes 1: “R” represents read enabled, and “W” represents write enabled.
2: This function is valid only when the timer 1 count start synchronous circuit is selected (I10=“1”).
3: This function is valid only when the timer 3 count start synchronous circuit is selected (I20=“1”).
R/W
TAW3/TW3A
Rev.3.01 2005.06.15 page 34 of 157
REJ03B0008-0301