ATA8742-PXQW Atmel, ATA8742-PXQW Datasheet - Page 117

MCU W/TRANSMITTER ASK/FSK 24QFN

ATA8742-PXQW

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

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

Available stocks

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Manufacturer
Quantity
Price
Part Number:
ATA8742-PXQW
Manufacturer:
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21.7.1
21.7.2
21.7.3
9151A–INDCO–07/09
Force Output Compare
Compare Match Blocking by TCNT1 Write
Using the Output Compare Unit
prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the out-
put glitch-free.
The OCR1x Register access may seem complex, but this is not case. When the double buffering
is enabled, the CPU has access to the OCR1x Buffer Register, and if double buffering is dis-
abled the CPU will access the OCR1x directly. The content of the OCR1x (Buffer or Compare)
Register is only changed by a write operation (the Timer/Counter does not update this register
automatically as the TCNT1 and ICR1 Register). Therefore OCR1x is not read via the high byte
temporary register (TEMP). However, it is a good practice to read the low byte first as when
accessing other 16-bit registers. Writing the OCR1x Registers must be done via the TEMP Reg-
ister since the compare of all 16 bits is done continuously. The high byte (OCR1xH) has to be
written first. When the high byte I/O location is written by the CPU, the TEMP Register will be
updated by the value written. Then when the low byte (OCR1xL) is written to the lower eight bits,
the high byte will be copied into the upper 8-bits of either the OCR1x buffer or OCR1x Compare
Register in the same system clock cycle.
For more information of how to access the 16-bit registers refer to
on page
In non-PWM Waveform Generation modes, the match output of the comparator can be forced by
writing a one to the Force Output Compare (1x) bit. Forcing compare match will not set the
OCF1x flag or reload/clear the timer, but the OC1x pin will be updated as if a real compare
match had occurred (the COM11:0 bits settings define whether the OC1x pin is set, cleared or
toggled).
All CPU writes to the TCNT1 Register will block any compare match that occurs in the next timer
clock cycle, even when the timer is stopped. This feature allows OCR1x to be initialized to the
same value as TCNT1 without triggering an interrupt when the Timer/Counter clock is enabled.
Since writing TCNT1 in any mode of operation will block all compare matches for one timer clock
cycle, there are risks involved when changing TCNT1 when using any of the Output Compare
channels, independent of whether the Timer/Counter is running or not. If the value written to
TCNT1 equals the OCR1x value, the compare match will be missed, resulting in incorrect wave-
form generation. Do not write the TCNT1 equal to TOP in PWM modes with variable TOP
values. The compare match for the TOP will be ignored and the counter will continue to 0xFFFF.
Similarly, do not write the TCNT1 value equal to BOTTOM when the counter is downcounting.
The setup of the OC1x should be performed before setting the Data Direction Register for the
port pin to output. The easiest way of setting the OC1x value is to use the Force Output Com-
pare (1x) strobe bits in Normal mode. The OC1x Register keeps its value even when changing
between Waveform Generation modes.
Be aware that the COM1x1:0 bits are not double buffered together with the compare value.
Changing the COM1x1:0 bits will take effect immediately.
110.
“Accessing 16-bit Registers”
ATA8742
117

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