ATTINY24A-PU Atmel, ATTINY24A-PU Datasheet - Page 55

• Manufacturer Part Number: ATTINY24A-PU
• Description: MCU AVR 2K FLASH 20MHZ 14PDIP
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY24A-PU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 12
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 128 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: 14-DIP (0.300", 7.62mm)
• Processor Series: ATTINY2x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 128 B
• Interface Type: SPI, USI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 12
• Number Of Timers: 2
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 20 Channel
• Data Rom Size: 128 B
• A/d Bit Size: 10 bit
• A/d Channels Available: 20
• Height: 5.33 mm
• Length: 19.68 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 1.8 V
• Width: 7.11 mm
• For Use With: ATSTK505 - ADAPTER KIT FOR 14PIN AVR MCU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10.1.2
10.1.3
10.1.4
8183C–AVR–03/11
Toggling the Pin
Switching Between Input and Output
Reading the Pin Value
Writing a logic one to PINxn toggles the value of PORTxn, independent on the value of DDRxn.
Note that the SBI instruction can be used to toggle one single bit in a port.
When switching between tri-state ({DDxn, PORTxn} = 0b00) and output high ({DDxn, PORTxn}
= 0b11), an intermediate state with either pull-up enabled {DDxn, PORTxn} = 0b01) or output
low ({DDxn, PORTxn} = 0b10) must occur. Normally, the pull-up enabled state is fully accept-
able, as a high-impedant environment will not notice the difference between a strong high driver
and a pull-up. If this is not the case, the PUD bit in the MCUCR 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}
= 0b10) as an intermediate step.
Table 10-1
Table 10-1.
Independent of the setting of Data Direction bit DDxn, the port pin can be read through the
PINxn Register bit. As shown in
ing 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.
shows a timing diagram of the synchronization when reading an externally applied pin value.
The maximum and minimum propagation delays are denoted t
Figure 10-3.
DDxn
0
0
0
1
1
PORTxn
summarizes the control signals for the pin value.
INSTRUCTIONS
0
1
1
0
1
Port Pin Configurations
SYSTEM CLK
SYNC LATCH
Synchronization when Reading an Externally Applied Pin value
PINxn
(in MCUCR)
r17
PUD
X
X
X
0
1
Figure 10-2 on page
XXX
Output
Output
Input
Input
Input
I/O
t
pd, max
Pull-up
0x00
Yes
No
No
No
No
XXX
54, the PINxn Register bit and the preced-
t
pd, min
Comment
Output Low (Sink)
Tri-state (Hi-Z)
Pxn will source current if ext. pulled low
Tri-state (Hi-Z)
Output High (Source)
ATtiny24A/44A/84A
pd,max
in r17, PINx
and t
pd,min
0xFF
respectively.
Figure 10-3
55