ATA8742-PXQW Atmel, ATA8742-PXQW Datasheet - Page 113

• Manufacturer Part Number: ATA8742-PXQW
• Description: MCU W/TRANSMITTER ASK/FSK 24QFN
• Manufacturer: Atmel

Specifications of ATA8742-PXQW

• Frequency: 433MHz
• Applications: Home Automation, Remote Sensing, RKE
• Modulation Or Protocol: ASK, FSK
• Data Rate - Maximum: 32 kBit/s
• Power - Output: 7.5dBm
• Current - Transmitting: 9.8mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Memory Size: 4kB Flash, 256B EEPROM, 256B SRAM
• Voltage - Supply: 2 V ~ 4 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 24-VQFN Exposed Pad, 24-HVQFN, 24-SQFN, 24-DHVQFN
• Processor Series: ATA8x
• Core: AVR8
• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 4 KB
• Data Ram Size: 256 B
• Interface Type: SPI, USI
• Maximum Clock Frequency: 8.1 MHz
• Number Of Programmable I/os: 12
• Number Of Timers: 2
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: ATASTK512-EK1-IND
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Lead Free Status / Rohs Status: Details

21.5
9151A–INDCO–07/09
Counter Unit
The main part of the 16-bit Timer/Counter is the programmable 16-bit bi-directional counter unit.
Figure 21-2 on page 113
Figure 21-2. Counter Unit Block Diagram
Signal description (internal signals):
The 16-bit counter is mapped into two 8-bit I/O memory locations: Counter High (TCNT1H) con-
taining the upper eight bits of the counter, and Counter Low (TCNT1L) containing the lower eight
bits. The TCNT1H Register can only be indirectly accessed by the CPU. When the CPU does an
access to the TCNT1H I/O location, the CPU accesses the high byte temporary register (TEMP).
The temporary register is updated with the TCNT1H value when the TCNT1L is read, and
TCNT1H is updated with the temporary register value when TCNT1L is written. This allows the
CPU to read or write the entire 16-bit counter value within one clock cycle via the 8-bit data bus.
It is important to notice that there are special cases of writing to the TCNT1 Register when the
counter is counting that will give unpredictable results. The special cases are described in the
sections where they are of importance.
Depending on the mode of operation used, the counter is cleared, incremented, or decremented
at each timer clock (clk
selected by the Clock Select bits (CS12:0). When no clock source is selected (CS12:0 = 0) the
timer is stopped. However, the TCNT1 value can be accessed by the CPU, independent of
whether clk
count operations.
The counting sequence is determined by the setting of the Waveform Generation mode bits
(WGM13:0) located in the Timer/Counter Control Registers A and B (TCCR1A and TCCR1B).
There are close connections between how the counter behaves (counts) and how waveforms
are generated on the Output Compare outputs OC1x. For more details about advanced counting
sequences and waveform generation, see
Count
Direction
Clear
clk
TOP
BOTTOM
T
1
TCNTnH (8-bit)
TEMP (8-bit)
T
1
is present or not. A CPU write overrides (has priority over) all counter clear or
TCNTn (16-bit Counter)
DATA BUS
T
1
). The clk
TCNTnL (8-bit)
shows a block diagram of the counter and its surroundings.
(8-bit)
Increment or decrement TCNT1 by 1.
Select between increment and decrement.
Clear TCNT1 (set all bits to zero).
Timer/Counter clock.
Signalize that TCNT1 has reached maximum value.
Signalize that TCNT1 has reached minimum value (zero).
T
1
can be generated from an external or internal clock source,
Direction
Count
Clear
“Modes of Operation” on page
Control Logic
TOP
BOTTOM
TOVn
(Int.Req.)
clk
Tn
Clock Select
( From Prescaler )
Detector
Edge
119.
ATA8742
Tn
113