EVAL-ADUC842QSZ Analog Devices Inc, EVAL-ADUC842QSZ Datasheet - Page 54

• 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
TIME INTERVAL COUNTER (TIC)
A TIC is provided on-chip for counting longer intervals than
the standard 8051 compatible timers are capable of. The TIC is
capable of timeout intervals ranging from 1/128 second to 255
hours. Furthermore, this counter is clocked by the external
32.768 kHz crystal rather than by the core clock, and it has the
ability to remain active in power-down mode and time long
power-down intervals. This has obvious applications for remote
battery-powered sensors where regular widely spaced readings
are required.
Six SFRs are associated with the time interval counter, TIMECON
being its control register. Depending on the configuration of the
IT0 and IT1 bits in TIMECON, the selected time counter regis-
ter overflow clocks the interval counter. When this counter is
equal to the time interval value loaded in the INTVAL SFR, the
TII bit (TIMECON.2) is set and generates an interrupt if enabled.
If the part is in power-down mode, again with TIC interrupt
enabled, the TII bit wakes up the device and resumes code
execution by vectoring directly to the TIC interrupt service
vector address at 0053H. The TIC-related SFRs are described in
Table 24. Note also that the time based SFRs can be written
initially with the current time; the TIC can then be controlled
and accessed by user software. In effect, this facilitates the
implementation of a real-time clock. A block diagram of the
TIC is shown in Figure 56.
The TIC is clocked directly from a 32 kHz external crystal on
the ADuC842/ADuC843 and by the internal 32 kHz ±10% R/C
oscillator on the ADuC841. Due to this, instructions that access
the TIC registers will also be clocked at this speed. The user
should ensure that there is sufficient time between instructions
to these registers to allow them to execute correctly.
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TIME INTERVAL COUNTER INTERRUPT
TCEN
INTERVAL TIMEOUT
32.768kHz EXTERNAL CRYSTAL
HUNDREDTHS COUNTER
SECOND COUNTER
MINUTE COUNTER
Figure 56. TIC, Simplified Block Diagram
HOUR COUNTER
PRESCALER
HOUR
8-BIT
HTHSEC
SEC
MIN
INTERVAL COUNTER
COUNT = INTVAL
TIMER INTVAL
COMPARE
INTVAL
8-BIT
SELECTION
TIMEBASE
INTERVAL
ITS0, 1
MUX
TIEN