Intel 8XC196MH Microscope & Magnifier User Manual


 
C-53
REGISTERS
T1CONTROL
T1CONTROL
Address:
Reset State:
1F78H
00H
The timer 1 control (T1CONTROL) register determines the clock source, counting direction, and count
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.
0 = disables timer
1 = enables timer
6 UD Up/Down
This bit determines the timer counting direction, in selected modes (see
mode bits, M2:0).
0 = count down
1 = count up
5:3 M2:0 EPA Clock Direction Mode Bits
These bits determine the timer clocking source and direction control
source.
M2 M1 M0 Clock Source Direction Source
000F
XTAL1
/4 UD bit (T1CONTROL.6)
X 0 1 T1CLK pin
UD bit (T1CONTROL.6)
010F
XTAL1
/4 T1DIR pin
011T1CLK pin
T1DIR pin
111quadrature clocking using T1CLK and T1DIR
If an external clock is selected, the timer counts on both the rising
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
000divide by 1 (disabled) 250 ns
001divide by 2 500 ns
010divide by 4 1 µs
011divide by 8 2 µs
100divide by 16 4 µs
101divide by 32 8 µs
110divide by 64 16 µs
111enable T1RELOAD
At 16 MHz. Use the formula on page 11-6 to calculate the resolution
at other frequencies.