ATMEGA162L-8AI Atmel, ATMEGA162L-8AI Datasheet - Page 63

• Manufacturer Part Number: ATMEGA162L-8AI
• Description: IC MCU AVR 16K 3V 8MHZ 44-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA162L-8AI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: EBI/EMI, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 35
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Data Converters: -

Reading the Pin Value
2513C–AVR–09/02
enabled state is fully acceptable, as a high-impedant environment will not notice the dif-
ference between a strong high driver and a pull-up. If this is not the case, the PUD bit in
the SFIOR Register can be set to disable all pull-ups in all ports.
Switching between input with pull-up and output low generates the same problem. The
user must use either the tri-state ({DDxn, PORTxn} = 0b00) or the output high state
({DDxn, PORTxn} = 0b11) as an intermediate step.
Table 27 summarizes the control signals for the pin value.
Table 27. Port Pin Configurations
Independent of the setting of Data Direction bit DDxn, the port pin can be read through
the PINxn Register bit. As shown in Figure 29, the PINxn Register bit and the preceding
latch constitute a synchronizer. This is needed to avoid metastability if the physical pin
changes value near the edge of the internal clock, but it also introduces a delay. Figure
30 shows a timing diagram of the synchronization when reading an externally applied
pin value. The maximum and minimum propagation delays are denoted t
respectively.
Figure 30. Synchronization when Reading an Externally Applied Pin Value
DDxn
INSTRUCTIONS
0
0
0
1
1
SYSTEM CLK
SYNC LATCH
PORTxn
0
1
1
0
1
PINxn
r17
(in SFIOR)
PUD
X
X
X
0
1
XXX
Output
Output
Input
Input
Input
I/O
Pull-up
t
pd, max
Yes
No
No
No
No
0x00
XXX
t
pd, min
ATmega162(V/U/L)
Comment
Tri-state (Hi-Z)
Pxn will source current if ext. pulled
low.
Tri-state (Hi-Z)
Output Low (Sink)
Output High (Source)
in r17, PINx
pd,max
0xFF
and t
pd,min
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