AT90S2313-4PI Atmel, AT90S2313-4PI Datasheet - Page 32

• Manufacturer Part Number: AT90S2313-4PI
• Description: IC MCU 2K 4MHZ UART LV IT 20DIP
• Manufacturer: Atmel
• Series: AVR® 90Sr

Specifications of AT90S2313-4PI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 15
• 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): 2.7 V ~ 6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Data Converters: -

Timer/Counter1 Control
Register B – TCCR1B
32
AT90S2313
• Bits 1, 0 – PWM11, PWM10: Pulse Width Modulator Select Bits
These bits select PWM operation of Timer/Counter1 as specified in Table 9. This mode
is described on page 35.
Table 9. PWM Mode Select
• Bit 7 – ICNC1: Input Capture1 Noise Canceler (4 CKs)
When the ICNC1 bit is cleared (zero), the input capture trigger noise canceler function is
disabled. The input capture is triggered at the first rising/falling edge sampled on the ICP
(input capture pin) as specified. When the ICNC1 bit is set (one), four successive sam-
ples are measured on the ICP (input capture pin), and all samples must be high/low
according to the input capture trigger specification in the ICES1 bit. The actual sampling
frequency is the XTAL clock frequency.
• Bit 6 – ICES1: Input Capture1 Edge Select
While the ICES1 bit is cleared (zero), the Timer/Counter1 contents are transferred to the
Input Capture Register (ICR1) on the falling edge of the input capture pin (ICP). While
the ICES1 bit is set (one), the Timer/Counter1 contents are transferred to the Input Cap-
ture Register (ICR1) on the rising edge of the input capture pin (ICP).
• Bits 5, 4 – Res: Reserved Bits
These bits are reserved bits in the AT90S2313 and always read zero.
• Bit 3 – CTC1: Clear Timer/Counter1 on Compare Match
When the CTC1 control bit is set (one), the Timer/Counter1 is reset to $0000 in the clock
cycle after a compareA match. If the CTC1 control bit is cleared, Timer/Counter1 contin-
ues counting and is unaffected by a compare match. Since the compare match is
detected in the CPU clock cycle following the match, this function will behave differently
when a prescaling higher than 1 is used for the timer. When a prescaling of 1 is used,
and the Compare A Register is set to C, the timer will count as follows if CTC1 is set:
... | C-2 | C-1 | C | 0 | 1 |...
When the prescaler is set to divide by 8, the timer will count like this:
... | C-2, C-2, C-2, C-2, C-2, C-2, C-2, C-2 | C-1, C-1, C-1, C-1, C-1, C-1, C-1, C-1 | C, 0,
0, 0, 0, 0, 0, 0 |...
In PWM mode, this bit has no effect.
Bit
$2E ($4E)
Read/Write
Initial value
PWM11
0
0
1
1
ICNC1
R/W
7
0
PWM10
0
1
0
1
ICES1
R/W
6
0
Description
PWM operation of Timer/Counter1 is disabled
Timer/Counter1 is an 8-bit PWM
Timer/Counter1 is a 9-bit PWM
Timer/Counter1 is a 10-bit PWM
R
5
–
0
R
4
–
0
CTC1
R/W
3
0
CS12
R/W
2
0
CS11
R/W
1
0
CS10
R/W
0
0
0839I–AVR–06/02
TCCR1B