EVAL-ADUC842QSZ Analog Devices Inc, EVAL-ADUC842QSZ Datasheet - Page 64

• Manufacturer Part Number: EVAL-ADUC842QSZ
• Description: Analog MCU Evaluation Board
• Manufacturer: Analog Devices Inc
• Series: QuickStart™ Kitr
• Type: MCUr

Specifications of EVAL-ADUC842QSZ

• Silicon Manufacturer: Analog Devices
• Core Architecture: 8052
• Silicon Core Number: ADuC842
• Tool / Board Applications: General Purpose MCU, MPU, DSP, DSC
• Mcu Supported Families: ADUC8xx
• Contents: Evaluation Board, Power Supply, Cable, Software and Documentation
• Development Tool Type: Hardware - Eval/Demo Board
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: ADuC824
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

ADuC841/ADuC842/ADuC843
TIMER/COUNTER OPERATING 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 31.
Table 31. T2CON Operating Modes
RCLK (or) TCLK
0
0
1
X
16-Bit Autoreload Mode
Autoreload mode has two options that 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 registers to be
reloaded with the 16-bit value in registers RCAP2L and RCAP2H,
which are preset by software. If EXEN2 = 1, then Timer 2 still
performs the above, but with the added feature that a 1-to-0
transition at external input T2EX will also trigger the 16-bit
reload and set EXF2. Autoreload mode is illustrated in Figure 70.
CAP2
0
1
X
X
* CORE CLK IS DEFINED BY THE CD BITS IN PLLCON
T2EX
* CORE CLK IS DEFINED BY THE CD BITS IN PLLCON
T2EX
PIN
PIN
PIN
PIN
CORE
CORE
CLK *
CLK*
T2
T2
TRANSITION
TR2
1
1
1
0
TRANSITION
DETECTOR
DETECTOR
Mode
16-Bit Autoreload
16-Bit Capture
Baud Rate
OFF
C/ T2 = 0
C/ T2 = 1
C/T2 = 0
C/T2 = 1
EXEN2
EXEN2
Figure 70. Timer/Counter 2, 16-Bit Autoreload Mode
Figure 71. Timer/Counter 2, 16-Bit Capture Mode
CONTROL
CONTROL
TR2
TR2
CONTROL
CONTROL
RELOAD
CAPTURE
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RCAP2L
(8 BITS)
RCAP2L
(8 BITS)
TL2
TL2
RCAP2H
16-Bit Capture Mode
Capture mode also has two options that 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 interrupt. If
EXEN2 = 1, then Timer 2 still performs the above, 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
registers RCAP2L and RCAP2H, respectively. In addition, the
transition at T2EX causes Bit EXF2 in T2CON to be set, and
EXF2, like TF2, can generate an interrupt. Capture mode is
illustrated in Figure 71. 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 will not occur. Therefore, Timer 2
interrupts will not occur, so they do not have to be disabled. In
this mode, the EXF2 flag, however, can still cause interrupts,
which can be used as a third external interrupt. Baud rate
generation is described as part of the UART serial port
operation in the following section.
(8 BITS)
RCAP2H
(8 BITS)
TH2
TH2
EXF2
TF2
EXF2
TF2
TIMER
INTERRUPT
TIMER
INTERRUPT