AT89LP52-20MU Atmel, AT89LP52-20MU Datasheet - Page 47

• Manufacturer Part Number: AT89LP52-20MU
• Description: IC MCU 8051 8K FLASH SPI 44VQFN
• Manufacturer: Atmel
• Series: 89LPr

Specifications of AT89LP52-20MU

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.4 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-VFQFN Exposed Pad
• Processor Series: AT89x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: Serial
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details

11.3
11.4
3709B–MICRO–12/10
Mode 2 – 8-bit Auto-Reload Timer/Counter
Mode 3 – 8-bit Split Timer
Mode 2 configures the Timer register as an 8-bit Counter (TL1) with automatic reload, as shown
in
TH1, which is preset by software. The reload leaves TH1 unchanged. Mode 2 operation is the
same for Timer/Counter 0.
Figure 11-3. Timer/Counter 1 Mode 2: 8-bit Auto-Reload
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
is 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
AT89LP51/52 can appear to have four 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
Figure
OSC
OSC
OSC
Figure
11-3. Overflow from TL1 not only sets TF1, but also reloads TL1 with the contents of
INT0 Pin
INT0 Pin
GATE0
T1 Pin
÷CDV
GATE1
T0 Pin
Mode 2:
÷CDV
÷CDV
11-4. TL0 uses the Timer 0 control bits: C/T, GATE0, TR0, INT0, and TF0. TH0
÷TPS
TR1
÷TPS
÷TPS
Time-out Period
C/T = 0
C/T = 1
C/T = 0
C/T =1
AT89LP51/52 - Preliminary
=
------------------------------------------------- -
System Frequency
Control
Control
Control
(
256 TH0
–
(8 Bits)
(8 Bits)
(8 Bits)
(8 Bits)
TH1
TL1
)
×
(
TPS
Reload
+
1
TF1
)
Inter r up t
Inter r up t
Inter r up t
47