Renesas Hitachi H8S/2194 Series Hardware Manual page 319

Bit 3: Selection of the Clock Source and Prescaler (TMA3)
This bit works to select the PSS or PSW as the clock source for the Timer A.
Bit 3
TMA3 Description
0 Selects the PSS as the clock source for the Timer A
1 Selects the PSW as the clock source for the Timer A
Bits 2 to 0: Clock Selection (TMA2 to TMA0)
These bits work to select the clock to input to the TCA. In combination with the TMA3 bit, the
choices are as follows:
Bit 3 Bit 2 Bit 1
TMA3 TMA2 TMA1
0 0 0
1
1 0
1
1 0 0
1
1 0
1
Note: φ = f osc
Rev. 2.0, 11/00, page 292 of 1037
Bit 0
Prescaler division ratio (interval timer)
TMA0 or overflow cycle (time base)
PSS, φ/16384 (Initial value)
0
PSS, φ/8192
1
PSS, φ/4096
0
PSS, φ/1024
1
PSS, φ/512
0
PSS, φ/256
1
PSS, φ/64
0
PSS, φ/16
1
0 1s
1 0.5s
0 0.25s
1 0.03125s
0 Works to clear the PSW and TCA to H'00
1
0
1
(Initial value)
Operation
mode
Interval
timer mode
Clock time
base mode