AT89LP6440 Atmel Corporation, AT89LP6440 Datasheet - Page 76

• Manufacturer Part Number: AT89LP6440
• Manufacturer: Atmel Corporation

Specifications of AT89LP6440

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 38
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 153.8
• Sram (kbytes): 4.25
• Eeprom (bytes): 8192
• Self Program Memory: IAP
• Operating Voltage (vcc): 2.4 to 3.6
• Timers: 3
• Isp: SPI/OCD
• Watchdog: Yes

13.3.1.1
13.3.1.2
13.3.1.3
76
AT89LP3240/6440
Normal Mode
Clear-Timer-on-Compare Mode
Dual-Slope Mode
The simplest waveform mode is when CP/RL2 = 0 and T2CM1-0 = 01B. In this mode the fre-
quency of the output is determined by the TOP value stored in RCAP2L and RCAP2H and
output edges occur at fractions of the timer period.
two waveforms of the same frequency but different phase by using the toggle on match action.
More complex waveforms are achieved by changing the TOP value and the compare values
more frequently.
Figure 13-4. Normal Mode Waveform Example
Clear-Timer-on-Compare (CTC) mode occurs when the CTCx bit of a compare channel is set to
one. CTC Mode works best when Timer 2 is in capture mode (CP/RL2 = 1) to allow the full range
of compare values. In CTC Mode the compare value defines the interval between output events
because the timer is cleared after every compare match.
form using the toggle on match action in CTC Mode.
Figure 13-5. CTC Mode Waveform Example
The dual-slope mode occurs when CP/RL2 = 0 and T2CM
of the output is determined by the TOP value stored in RCAP2L and RCAP2H and output edges
occur at fractions of the timer period on both the up and down count.
example of outputting two symmetrical waveforms using the toggle on match action. More com-
plex waveforms are achieved by changing the TOP value and the compare values more
frequently.
{RCAP2H,RCA2L}
{CCAH,CCAL}
{CCAH,CCAL}
{CCBH,CCBL}
CCA
CCA
CCB
CP/RL2 = 0, T2CM
Figure 13-4
CP/RL2 = 1
1-0
Figure 13-5
1-0
= 01B, DCEN = 0
= 1xB. In this mode the frequency
shows an example of outputting
shows an example wave-
Figure 13-6
3706C–MICRO–2/11
shows an