Specifications

C8051F330/1
170 Rev. 1.1
Setting the TR0 bit (TCON.4) enables the timer when either GATE0 (TMOD.3) is logic 0 or the input signal /INT0 is
active as defined by bit IN0PL in register INT01CF (see
Figure 8.13). Setting GATE0 to ‘1’ allows the timer to be
controlled by the external input signal /INT0 (see Section “8.3.5. Interrupt Register Descriptions” on page 61),
facilitating pulse width measurements.
Setting TR0 does not force the timer to reset. The timer registers should be loaded with the desired initial value before
the timer is enabled.
TL1 and TH1 form the 13-bit register for Timer 1 in the same manner as described above for TL0 and TH0. Timer 1
is configured and controlled using the relevant TCON and TMOD bits just as with Timer
0. The input signal /INT1 is
used with Timer
1; the /INT1 polarity is defined by bit IN1PL in register INT01CF (see Figure 8.13).
18.1.2. Mode 1: 16-bit Counter/Timer
Mode 1 operation is the same as Mode 0, except that the counter/timer registers use all 16 bits. The counter/timers are
enabled and configured in Mode
1 in the same manner as for Mode 0.
TR0 GATE0 /INT0 Counter/Timer
0XXDisabled
1 0 X Enabled
110Disabled
111Enabled
X = Don't Care
Figure 18.1. T0 Mode 0 Block Diagram
TCLK
TL0
(5 bits)
TH0
(8 bits)
TCON
TF0
TR0
TR1
TF1
IE1
IT1
IE0
IT0
Interrupt
TR0
0
1
0
1
SYSCLK
Pre-scaled Clock
CKCON
T
3
M
H
T
3
M
L
S
C
A
0
S
C
A
1
T
0
M
T
2
M
H
T
2
M
L
T
1
M
TMOD
T
1
M
1
T
1
M
0
C
/
T
1
G
A
T
E
1
G
A
T
E
0
C
/
T
0
T
0
M
1
T
0
M
0
GATE0
/INT0
T0
Crossbar
INT01CF
I
N
1
S
L
1
I
N
1
S
L
0
I
N
1
S
L
2
I
N
1
P
L
I
N
0
P
L
I
N
0
S
L
2
I
N
0
S
L
1
I
N
0
S
L
0
IN0PL
XOR