ATMEGA325A-MU Atmel, ATMEGA325A-MU Datasheet - Page 251

• Manufacturer Part Number: ATMEGA325A-MU
• Description: IC MCU AVR 32K FLASH 64VQFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA325A-MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

24.6
8285B–AVR–03/11
Boundary-scan Order
ATmega165A/165PA/325A/325PA/3250A/3250PA/6
The recommended values from
in the algorithm in
are shown. The column “Actions” describes what JTAG instruction to be used before filling the
Boundary-scan Register with the succeeding columns. The verification should be done on the
data scanned out when scanning in the data on the same row in the table.
Table 24-4.
Using this algorithm, the timing constraint on the HOLD signal constrains the TCK clock fre-
quency. As the algorithm keeps HOLD high for five steps, the TCK clock frequency has to be at
least five times the number of scan bits divided by the maximum hold time, t
Table 24-5
selected as data path. Bit 0 is the LSB; the first bit scanned in, and the first bit scanned out. The
scan order follows the pin-out order as far as possible. Therefore, the bits of Port A is scanned in
the opposite bit order of the other ports. Exceptions from the rules are the Scan chains for the
analog circuits, which constitute the most significant bits of the scan chain regardless of which
physical pin they are connected to. In
Step
1
2
3
4
5
6
7
8
9
10
11
Actions
SAMPLE_P
RELOAD
EXTEST
Verify the
COMP bit
scanned out
to be 0
Verify the
COMP bit
scanned out
to be 1
shows the Scan order between TDI and TDO when the Boundary-scan chain is
Algorithm for Using the ADC
Table 24-4 on page
ADCEN
1
1
1
1
1
1
1
1
1
1
1
DAC
Table 24-3 on page 248
0x200
0x200
0x200
0x123
0x123
0x200
0x200
0x200
0x143
0x143
0x200
251. Only the DAC and port pin values of the Scan Chain
Figure
MUXEN
0x08
0x08
0x08
0x08
0x08
0x08
0x08
0x08
0x08
0x08
0x08
24-3, PXn Data corresponds to FF0, PXn Control
HOLD
1
0
1
1
1
1
0
1
1
1
1
are used unless other values are given
PRECH
1
1
1
1
0
1
1
1
1
0
1
PA3.
Data
0
0
0
0
0
0
0
0
0
0
0
hold,max
PA3.
Control
0
0
0
0
0
0
0
0
0
0
0
PA3.
Pull-up_
Enable
0
0
0
0
0
0
0
0
0
0
0
251