AT89LP52-20PU Atmel, AT89LP52-20PU Datasheet - Page 59

• Manufacturer Part Number: AT89LP52-20PU
• Description: IC MCU 8051 8K FLASH SPI 40PDIP
• Manufacturer: Atmel
• Series: 89LPr

Specifications of AT89LP52-20PU

• 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: 40-DIP (0.600", 15.24mm)
• 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: Through Hole
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details

Table 14-2.
14.2.2
3709B–MICRO–12/10
Modes 1, 3 Max: 750K
Mode 0 Max: 6 MHz
Mode 2 Max: 750K
Baud Rate
19.2K
137.5
19.2K
137.5
9.6K
4.8K
2.4K
1.2K
9.6K
4.8K
2.4K
1.2K
110
110
110
110
Using Timer 2 to Generate Baud Rates
Commonly Used Baud Rates Generated by Timer 1
The Timer 1 overflow rate normally determines the baud rates in Modes 1 and 3. When Timer 1
is the baud rate generator, the baud rates are determined by the Timer 1 overflow rate and the
value of SMOD1 according to the following equation:
The Timer 1 interrupt should be disabled in this application. The Timer itself can be configured
for either timer or counter operation in any of its 3 running modes. In the most typical applica-
tions, it is configured for timer operation in auto-reload mode (high nibble of TMOD = 0010B). In
this case, the baud rate is given by the following formula:
Table 14-2
Timer 2 is selected as the baud rate generator by setting TCLK and/or RCLK in T2CON. Under
these conditions, the baud rates for transmit and receive can be simultaneously different by
using Timer 1 for transmit and Timer 2 for receive, or vice versa. The baud rate generator mode
f
OSC
11.059
11.059
11.059
11.059
11.059
11.986
11.059
11.059
11.059
11.059
11.059
11.986
12
12
12
12
12
(MHz)
6
6
lists commonly used baud rates and how they can be obtained from Timer 1.
CDV
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Modes 1, 3
Baud Rate
Modes 1, 3
Baud Rate
SMOD1
0
0
1
1
1
1
0
0
0
0
1
0
1
0
0
0
0
0
0
=
2
------------------- -
=
SMOD1
32
2
------------------- -
SMOD1
32
C/T
×
X
X
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
AT89LP51/52 - Preliminary
System Frequency
------------------------------------------------- -
×
[
(Timer 1 Overflow Rate)
256
–
(
Mode
TH1
X
X
2
2
2
2
2
1
1
1
1
2
2
2
2
2
2
2
1
)
]
Timer 1
×
-------------------- -
TPS
TPS
1
0
0
0
0
0
0
0
0
0
5
5
5
5
5
5
5
5
0
0
+
1
Reload Value
FEEBH
FEE0H
F55CH
F2AFH
F2AFH
DCH
DCH
FDH
FDH
B8H
FAH
E8H
1DH
F4H
70H
F4H
72H
X
X
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