ATxmega16A4 Atmel Corporation, ATxmega16A4 Datasheet - Page 119

• Manufacturer Part Number: ATxmega16A4
• Manufacturer: Atmel Corporation

Specifications of ATxmega16A4

• Flash (kbytes): 16 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 34
• Ext Interrupts: 34
• Usb Speed: No
• Usb Interface: No
• Spi: 7
• Twi (i2c): 2
• Uart: 5
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 12
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 2
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 12
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 3.3
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.6 to 3.6
• Operating Voltage (vcc): 1.6 to 3.6
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 5
• Output Compare Channels: 16
• Input Capture Channels: 16
• Pwm Channels: 16
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

11.7
11.7.1
8077H–AVR–12/09
Registers Description
CTRL – Watchdog Timer Control Register
• Bits 7:6 - Reserved
These bits are unused and reserved for future use. For compatibility with future devices, always
write these bits to zero when this register is written.
• Bits 5:2 - PER[3:0]: Watchdog Timeout Period
These bits determine the Watchdog timeout period as a number of 1 kHz ULP oscillator cycles.
In window mode operation, these bits define the open window period. The different typical time-
out periods are found in
Timeout Period (WDP) fuses, and will be loaded at power-on.
In order to change these bits the CEN bit must be written to 1 at the same time. These bits are
protected by the Configuration Change Protection mechanism, for detailed description refer to
Section 3.12 ”Configuration Change Protection” on page
Table 11-1.
Bit
+0x00
Read/Write
(unlocked)
Read/Write
(locked)
Initial Value
(x = fuse)
PER[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Watchdog timeout periods
R
R
7
0
-
R
R
6
0
-
Table
Group Configuration
11-1. The initial values of these bits are set by the Watchdog
R/W
R
X
5
125CLK
250CLK
500CLK
1KCLK
2KCLK
4KCLK
8KCLK
16CLK
32CLK
64CLK
8CLK
R/W
R
4
X
PER[3:0]
R/W
R
X
3
12.
R/W
R
2
X
Typical timeout periods
ENABLE
R/W
R
X
1
Reserved
Reserved
Reserved
Reserved
Reserved
0.125 s
16 ms
32 ms
64 ms
0.25 s
8 ms
0.5 s
1.0 s
2.0 s
4.0 s
8.0 s
XMEGA A
CEN
R/W
R
0
0
CTRL
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