AP160 AMICC [AMIC Technology], AP160 Datasheet - Page 8

• Manufacturer Part Number: AP160
• Description: 8-BIT MICROCONTROLLER WITH 8KB OTP
• Manufacturer: AMICC [AMIC Technology]

Capture Mode
In the capture mode, two options are selected by bit EXEN2 in T2CON. If EXEN2=0, Timer 2 is a 16-bit timer or counter
which upon overflow sets bit TF2 in T2CON. This bit can then be used to generate an interrupt. If EXEN2=1, Timer 2
performs the same operation, but a 1-to-0 transition at external input T2EX also causes the current value in TH2 and TL2 to
be captured into RCAP2H and RCAP2L, respectively. In addition, the transition at T2EX causes bit EXF2 in T2CON to be
set. The EXF2 bit, like TF2, can generate an interrupt. The capture mode is illustrated in Figure 1.
Auto-Reload (UP or Down Counter)
Timer 2 can be programmed to count up or down when configured in its 16-bit auto-reload mode. This feature is invoked by
the DCEN (Down Counter Enable) bit located in the SFR T2MOD (see Table 3). Upon reset, the DCEN bit is set to 0 so that
Timer 2 will default to count up. When DCEN is set, Timer 2 can count up or down, depending on the value of the T2EX pin.
Figure 2 shows Timer 2 automatically counting up when DCEN=0.
Version 0.0
T2EX PIN
T2EX PIN
OSC
OSC
T2 PIN
T2 PIN
TRANSITION
DETECTOR
TRANSITION
DETECTOR
12
12
Figure 2. Timer 2 Auto Reload Mode (DCEN=0)
EXEN2
C/T2=0
EXEN2
C/T2=1
C/T2=0
C/T2=1
Figure 1. Timer in Capture Mode
CONTROL
CONTROL
RELOAD
CAPTURE
TR2
TR2
CONTROL
CONTROL
8
RCAP2H
TH2
RCAP2H
TH2
EXF2
RCAP2L
TL2
RCAP2L
TL2
OVERFLOW
OVERFLOW
EXF2
TF2
AMIC Technology, Inc.
TF2
INTERRUPT
TIMER 2
INTERRUPT
AP160
TIMER 2