Intel 8XC196MC User Manual
8XC196MC, MD, MH USER’S MANUAL
11-16
T1CONTROL
Address:
Reset State:
1F78H
00H
The timer 1 control (T1CONTROL) register determines the clock source, counting direction, and count
rate for timer 1.
rate for timer 1.
7
0
CE
UD
M2
M1
M0
P2
P1
P0
Bit
Number
Bit
Mnemonic
Function
7
CE
Counter Enable
This bit enables or disables the timer. From reset, the timers are
disabled and not free running.
disabled and not free running.
0 = disables timer
1 = enables timer
1 = enables timer
6
UD
Up/Down
This bit determines the timer counting direction, in selected modes (see
mode bits, M2:0).
mode bits, M2:0).
0 = count down
1 = count up
1 = count up
5:3
M2:0
EPA Clock Direction Mode Bits
These bits determine the timer clocking source and direction control
source.
source.
M2
M1
M0
Clock Source
Direction Source
0
0
0
F
XTAL
1
/4
UD bit (T1CONTROL.6)
X
0
1
T1CLK pin
†
UD bit (T1CONTROL.6)
0
1
0
F
XTAL
1
/4
T1DIR pin
0
1
1
T1CLK pin
†
T1DIR pin
1
1
1
quadrature clocking using T1CLK and T1DIR
†
If an external clock is selected, the timer counts on both the rising
and falling edges of the clock.
and falling edges of the clock.
2:0
P2:0
EPA Clock Prescaler Bits
These bits determine the clock prescaler value.
P2
P1
P0
Prescaler Divisor
Resolution
†
0
0
0
divide by 1 (disabled)
250 ns
0
0
1
divide by 2
500 ns
0
1
0
divide by 4
1 µs
0
1
1
divide by 8
2 µs
1
0
0
divide by 16
4 µs
1
0
1
divide by 32
8 µs
1
1
0
divide by 64
16 µs
1
1
1
enable T1RELOAD
—
†
At 16 MHz. Use the formula on page 11-6 to calculate the resolution
at other frequencies.
at other frequencies.
Figure 11-8. Timer 1 Control (T1CONTROL) Register