Hyundai gms90x51c Manual De Usuario
GMS90X5XC Series
HYUNDAI MicroElectronics
Jan. 2001 Ver 1.0
19
TIMER 2
Timer 2 is a 16-bit timer/Counter with an up/down count feature. It can operate either as timer or as an event
counter which is selected by bit C/T2 (T2CON.1). It has three operating modes as shown in Table 5.
counter which is selected by bit C/T2 (T2CON.1). It has three operating modes as shown in Table 5.
Note:
↓
=
falling edge
Table 5. Timer/Counter 2 Operating Modes
Mode
T2CON
T2MOD T2CON
P1.1/
T2EX
Remarks
Input Clock
RCLK or
TCLK
CP/RL2
TR2
DCEN
EXEN2
internal
external
(P1.0/T2)
16-bit Auto-
Reload
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
0
1
1
1
0
1
X
X
X
X
↓
0
1
1
reload upon over-
flow
reload trigger (fall-
ing edge)
Down counting
Up counting
flow
reload trigger (fall-
ing edge)
Down counting
Up counting
f
OSC
÷
12
Max.
f
OSC
÷
24
16-bit
Capture
0
0
1
1
1
1
X
X
0
1
X
↓
16 bit Timer/ Coun-
ter (only up-count-
ing)
capture TH2,TL2
ter (only up-count-
ing)
capture TH2,TL2
→
RC2H,RC2L
f
OSC
÷
12
Max.
f
OSC
÷
24
Baud Rate
Generator
1
1
X
X
1
1
X
X
0
1
X
↓
no overflow
interrupt request
(TF2)
extra external inter-
rupt ("Timer 2")
interrupt request
(TF2)
extra external inter-
rupt ("Timer 2")
f
OSC
÷
12
Max.
f
OSC
÷
24
Off
X
X
0
X
X
X
Timer 2 stops
-
-