AT89LP828-20JU Atmel, AT89LP828-20JU Datasheet - Page 44

• Manufacturer Part Number: AT89LP828-20JU
• Description: MCU 8051 8K FLASH SPI 32PLCC
• Manufacturer: Atmel
• Series: 89LPr

Specifications of AT89LP828-20JU

• 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: 8KB (8K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 1K 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-PLCC
• Processor Series: AT89x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: 2-Wire, SPI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 30
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: AT89ISP
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Details

11.4
44
Mode 3 – 8-bit Split Timer
AT89LP428/828
Timer 1 in Mode 3 simply holds its count. The effect is the same as setting TR1 = 0. Timer 0 in
Mode 3 establishes TL0 and TH0 as two separate counters. The logic for Mode 3 on Timer 0 is
shown in
locked into a timer function (counting clock cycles) and takes over the use of TR1 and TF1 from
Timer 1. Thus, TH0 now controls the Timer 1 interrupt. While Timer 0 is in Mode 3, Timer 1 will
still obey its settings in TMOD but cannot generate an interrupt.
Mode 3 is for applications requiring an extra 8-bit timer or counter. With Timer 0 in Mode 3, the
AT89LP428/828 can appear to have three Timer/Counters. When Timer 0 is in Mode 3, Timer 1
can be turned on and off by switching it out of and into its own Mode 3. In this case, Timer 1 can
still be used by the serial port as a baud rate generator or in any application not requiring an
interrupt.
Figure 11-4. Timer/Counter 0 Mode 3: Two 8-bit Counters
Note:
RH0/RL0 are not required by Timer 0 during Mode 3 and may be used as temporary storage
registers.
INT0 Pin
Figure
GATE
T0 Pin
11-4. TL0 uses the Timer 0 control bits: C/T, GATE, TR0, INT0, and TF0. TH0 is
÷TPS
÷TPS
C/T = 0
C/T =1
Control
Control
(8 Bits)
(8 Bits)
Interrupt
Interrupt
3654A–MICRO–8/09