AT89LP428-20AU Atmel, AT89LP428-20AU Datasheet - Page 49

• Manufacturer Part Number: AT89LP428-20AU
• Description: MCU 8051 4K FLASH SPI 32TQFP
• Manufacturer: Atmel
• Series: 89LPr

Specifications of AT89LP428-20AU

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 30
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 2.4 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-TQFP, 32-VQFP
• Processor Series: AT89x
• Core: 8051
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: AT89ISP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Details

11.5.3
3654A–MICRO–8/09
Mode 2 – 8-bit Frequency Generator
Figure 11-7. Timer/Counter 1 PWM Mode 1
Timer 0 in PWM mode 2 functions as an 8-bit Auto-reload timer, the same as normal Mode 2,
with the exception that the output pin T0 is toggled at every TL0 overflow (see
Figure 11-9 on page
used to output a square wave of varying frequency. THx acts as an 8-bit counter. The following
formula gives the output frequency for Timer 0 in PWM mode 2.
Figure 11-8. Timer/Counter 1 PWM Mode 2
Note:
INT1 Pin
GATE
{RH0 & RL0}/{RH1 & RL1} are not required by Timer 0/Timer 1 during PWM mode 2 and may be
used as temporary storage registers.
INT1 Pin
GATE
OSC
TR1
Mode 2:
TR1
50). Timer 1 in PWM mode 2 is identical to Timer 0. PWM mode 2 can be
OSC
÷TPS
Control
f
÷TPS
OUT
Control
=
Oscillator Frequency
------------------------------------------------------ -
2
×
(8 Bits)
(8 Bits)
(
RL1
256 TH0
TL1
–
(8 Bits)
(8 Bits)
TH1
TL1
)
×
(8 Bits)
(8 Bits)
OCR1
RH1
TH1
-------------------- -
TPS
AT89LP428/828
1
=
+
1
Figure 11-8
T1
T1
and
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