ATtiny2313 Atmel Corporation, ATtiny2313 Datasheet - Page 108

• Manufacturer Part Number: ATtiny2313
• Manufacturer: Atmel Corporation

Specifications of ATtiny2313

• Flash (kbytes): 2 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 4
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 18
• Ext Interrupts: 18
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 0.12
• Eeprom (bytes): 128
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

Timer/Counter1
Control Register C –
TCCR1C
Timer/Counter1 –
TCNT1H and TCNT1L
Output Compare
Register 1 A –
OCR1AH and OCR1AL
108
ATtiny2313
• Bit 7 – FOC1A: Force Output Compare for Channel A
• Bit 6 – FOC1B: Force Output Compare for Channel B
The FOC1A/FOC1B bits are only active when the WGM13:0 bits specifies a non-PWM mode.
However, for ensuring compatibility with future devices, these bits must be set to zero when
TCCR1A is written when operating in a PWM mode. When writing a logical one to the
FOC1A/FOC1B bit, an immediate compare match is forced on the Waveform Generation unit.
The OC1A/OC1B output is changed according to its COM1x1:0 bits setting. Note that the
FOC1A/FOC1B bits are implemented as strobes. Therefore it is the value present in the
COM1x1:0 bits that determine the effect of the forced compare.
A FOC1A/FOC1B strobe will not generate any interrupt nor will it clear the timer in Clear Timer
on Compare match (CTC) mode using OCR1A as TOP.
The FOC1A/FOC1B bits are always read as zero.
The two Timer/Counter I/O locations (TCNT1H and TCNT1L, combined TCNT1) give direct
access, both for read and for write operations, to the Timer/Counter unit 16-bit counter. To
ensure that both the high and low bytes are read and written simultaneously when the CPU
accesses these registers, the access is performed using an 8-bit temporary high byte register
(TEMP). This temporary register is shared by all the other 16-bit registers.
Registers” on page 84.
Modifying the counter (TCNT1) while the counter is running introduces a risk of missing a com-
pare match between TCNT1 and one of the OCR1x Registers.
Writing to the TCNT1 Register blocks (removes) the compare match on the following timer clock
for all compare units.
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
FOC1A
R/W
R/W
W
7
0
7
0
7
0
FOC1B
R/W
R/W
W
6
0
6
0
6
0
R/W
R/W
R
5
–
0
5
0
5
0
R/W
R/W
OCR1A[15:8]
R
TCNT1[15:8]
0
4
–
0
4
0
4
OCR1A[7:0]
TCNT1[7:0]
R/W
R/W
3
0
3
0
R
3
–
0
R/W
R/W
2
0
2
0
R
2
–
0
R/W
R/W
1
0
1
0
R
1
–
0
R/W
R/W
0
0
0
0
R
0
–
0
See “Accessing 16-bit
OCR1AH
OCR1AL
TCNT1H
TCNT1L
TCCR1C
2543L–AVR–08/10