AT89LP6440 Atmel Corporation, AT89LP6440 Datasheet - Page 64

• 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

Figure 12-2. Timer 2 Diagram: Auto-Reload Mode (DCEN = 0)
Figure 12-3. Timer 2 Waveform: Auto-Reload Mode (DCEN = 0)
12.3.2
64
AT89LP3240/6440
Up or Down Counter
BOTTOM
RCAP2L and then overflows. The overflow sets TF2 and causes the timer registers to be
reloaded with MIN. If EXEN2 = 1, a 1-to-0 transition on T2EX will clear the timer and set EXF2.
The Timer 2 overflow rate for this mode is given in the following equation:
Timer 2 Count Mode 1 is provided to support variable precision asymmetrical PWM in the CCA.
The value of TOP stored in RCAP2H and RCAP2L is double-buffered such that a new TOP
value takes affect only after an overflow. The behavior of Count Mode 0 versus Count Mode 1 is
shown in
Setting DCEN = 1 enables Timer 2 to count up or down, as shown in
the T2EX pin controls the direction of the count (if EXEN2 = 1). A logic 1 at T2EX makes Timer 2
count up. When T2CM
also causes BOTTOM, the 16-bit value in RCAP2H and RCAP2L, to be reloaded into the timer
MAX
MAX
TOP
MIN
MIN
DCEN = 0, T2CM = 01B
÷TPS
Auto-Reload Mode:
Figure
12-3.
1-0
= 00B, the timer will overflow at MAX and set the TF2 bit. This overflow
T2CM
T2CM
Time-out Period
1-0
1-0
= 00B, DCEN = 0
= 01B, DCEN = 0
TL2
=
TH2
{
----------------------------------------------------------------- -
RCAP2H RCAP2L
Oscillator Frequency
,
TF2 Set
TF2 Set
Figure
}
+
1
12-4. In this mode,
×
(
TPS
3706C–MICRO–2/11
+
1
)