E202075_HD404889 Datasheet, PDF (86/202 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip LCD Circuit

HD404889/HD404899/HD404878/HD404868 Series
Timer mode register A (TMA: $00F)
Bit
Read/Write
Initial value on reset
Bit name
3
2
1
0
W
W
W
W
0
0
0
0
TMA3 TMA2 TMA1 TMA0
TMA3 TMA2 TMA1 TMA0 Source prescaler Input clock period Operating mode
0
0
1
0
0
1
1
0
0
0
1
1
0
1
1
0
0
1
0
0
1
1
1
0
0
1
1
PSS
PSS
PSS
PSS
PSS
PSS
PSS
PSS
PSW
PSW
PSW
PSW
PSW
2,048 tcyc
1,024 tcyc
512 tcyc
128 tcyc
32 tcyc
8 tcyc
4 tcyc
2 tcyc
32 twcyc
16 twcyc
8 twcyc
2 twcyc
1/2 twcyc
Not Used
Timer A
mode
Time base
mode
* : Don't care
1
*
PSW, TCA reset
Notes:
1. twcyc = 244.14 µs (using 32.768 kHz crystal oscillator)
2. Timer/counter overflow output period (s) = input clock period (s) × 256.
3. If PSW and TCA reset is selected during LCD, the LCD enters the halt state
(power switch off). Therefore, to provide continuous LCD the PSW and TCA
reset interval must be minimized by the program.
4. The division ratio must not be changed while time base mode is being used, as this
will result in an error in the overflow period.
Figure 36 Timer Mode Register A (TMA)
84