ADUC832 Analog Devices, ADUC832 Datasheet - Page 74

• Manufacturer Part Number: ADUC832
• Description: Precision Analog Microcontroller: 1.3MIPS 8052 MCU + 62kB Flash + 8-Ch 12-Bit ADC + Dual 12-Bit DAC
• Manufacturer: Analog Devices

Specifications of ADUC832

• Mcu Core: 8052
• Mcu Speed (mips): 1.3
• Sram (bytes): 2304Bytes
• Gpio Pins: 34
• Adc # Channels: 8
• Other: PWM

ADuC832
TIMER/COUNTER OPERATION MODES
The following sections describe the operating modes for Timer/
Counter 2. The operating modes are selected by bits in the T2CON
SFR as shown in Table 39.
Table 39. T2CON Operating Modes
RCLK (or) TCLK
0
0
1
X
16-Bit Autoreload Mode
In autoreload mode, there are two options, which are selected
by Bit EXEN2 in T2CON. If EXEN2 = 0, then when Timer 2
rolls over, it not only sets TF2 but also causes the Timer 2 regis-
ters to be reloaded with the 16-bit value in Register RCAP2L and
Register RCAP2H, which are preset by software. If EXEN2 = 1,
then Timer 2 still performs the same function as EXEN2 = 0,
but with the added feature that a 1-to-0 transition at External
Input T2EX also triggers the 16-bit reload and sets EXF2. The
autoreload mode is illustrated in Figure 79.
*CORE CLK IS DEFINED BY THE CD BITS IN PLLCON.
T2EX
T2EX
*CORE CLK IS DEFINED BY THE CD BITS IN PLLCON.
PIN
PIN
PIN
PIN
CAP2
0
1
X
X
CORE
CORE
CLK*
CLK*
T2
T2
TRANSITION
TRANSITION
DETECTOR
DETECTOR
÷12
÷12
TR2
1
1
1
0
C/T2 = 0
C/T2 = 1
C/T2 = 0
C/T2 = 1
Mode
16-bit autoreload
16-bit capture
Baud rate
Off
EXEN2
EXEN2
Figure 79. Timer/Counter 2, 16-Bit Autoreload Mode
CONTROL
Figure 80. Timer/Counter 2, 16-Bit Capture Mode
CONTROL
TR2
TR2
CONTROL
CONTROL
RELOAD
CAPTURE
Rev. A | Page 74 of 92
RCAP2L
RCAP2L
(8 BITS)
(8 BITS)
TL2
TL2
16-Bit Capture Mode
In the capture mode, there are again two options, which are
selected by Bit EXEN2 in T2CON. If EXEN2 = 0, then Timer 2
is a 16-bit timer or counter that, upon overflowing, sets Bit TF2,
the Timer 2 overflow bit, which can be used to generate an inter-
rupt. If EXEN2 = 1, then Timer 2 still performs the same function
as EXEN2 = 0, but a l-to-0 transition on External Input T2EX
causes the current value in the Timer 2 registers, TL2 and TH2,
to be captured into Register RCAP2L and Register RCAP2H,
respectively. In addition, the transition at T2EX causes Bit EXF2
in T2CON to be set, and EXF2, like TF2, can generate an inter-
rupt. The capture mode is illustrated in Figure 80.
The baud rate generator mode is selected by RCLK = 1 and/or
TCLK = 1.
In either case, if Timer 2 is being used to generate the baud rate,
the TF2 interrupt flag does not occur. Therefore, Timer 2 interrupts
do not occur, so they do not have to be disabled. In this mode,
the EXF2 flag, however, can still cause interrupts, and this can
be used as a third external interrupt.
Baud rate generation is described as part of the UART serial
port operation in the UART Serial Interface section.
RCAP2H
RCAP2H
(8 BITS)
(8 BITS)
TH2
TH2
EXF2
EXF2
TF2
TF2
TIMER
INTERRUPT
TIMER
INTERRUPT