HT48R0AA-1
In the event count or timer mode, once the Timer/Event
Counter 0/1 starts counting, it will count from the current
contents in the Timer/Event Counter 0/1 to FFH. Once
overflow occurs, the counter is reloaded from the
Timer/Event Counter 0/1 preload register and generates
the interrupt request flag (T0F/T1F; bit 5/6 of the INTC) at
the same time.
TMR0/TMR1 has received a transient from low to high
(or high to low if the T0E/T1E bits is ²0²) it will start
counting until the TMR0/TMR1 returns to the original
level and resets the T0ON/T1ON. The measured result
will remain in the Timer/Event Counter 0/1 even if the
activated transient occurs again. In other words, only
one cycle measurement can be done. Until setting the
T0ON/T1ON, the cycle measurement will function again
as long as it receives further transient pulse. Note that,
in this operating mode, the Timer/Event Counter 0/1
In the pulse width measurement mode with the
T0ON/T1ON and T0E/T1E bits equal to one, once the
Bit No.
Label
Function
Defines the prescaler stages, T0PSC2, T0PSC1, T0PSC0=
000: fINT=fSYS/2
001: fINT=fSYS/4
010: fINT=fSYS/8
011: fINT=fSYS/16
100: fINT=fSYS/32
101: fINT=fSYS/64
110: fINT=fSYS/128
111: fINT=fSYS/256
T0PSC0~
T0PSC2
0~2
Defines the TMR0 active edge of the timer/event counter:
In Event Counter Mode (T0M1,T0M0)=(0,1):
1:count on falling edge;
0:count on rising edge
3
T0E
In Pulse Width measurement mode (T0M1,T0M0)=(1,1):
1: start counting on the rising edge, stop on the falling edge;
0: start counting on the falling edge, stop on the rising edge
4
5
T0ON
Enable or disable timer 0 counting (0=disable; 1=enable)
¾
Unused bit, read as ²0²
Defines the operating mode (T0M1, T0M0)
01=Event count mode (external clock)
10=Timer mode (internal clock)
11=Pulse width measurement mode
00=Unused
6
7
T0M0
T0M1
TMR0C (0EH) Register
Bit No.
Label
Function
0~2
¾
Unused bit, read as ²0²
Defines the TMR1 active edge of the timer/event counter:
In Event Counter Mode (T1M1,T1M0)=(0,1):
1:count on falling edge;
0:count on rising edge
3
T1E
In Pulse Width measurement mode (T1M1,T1M0)=(1,1):
1: start counting on the rising edge, stop on the falling edge;
0: start counting on the falling edge, stop on the rising edge
4
5
T1ON
Enable or disable timer 1 counting (0=disabled; 1=enabled)
¾
Unused bit, read as²0²
Defines the operating mode (T1M1, T1M0)
01=Event count mode (external clock)
10=Timer mode (internal clock)
11=Pulse width measurement mode
00=Unused
6
7
T1M0
T1M1
TMR1C (11H) Register
Rev. 1.10
14
July 27, 2007
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
