AT89LP6440-20AU Atmel, AT89LP6440-20AU Datasheet - Page 87

• Manufacturer Part Number: AT89LP6440-20AU
• Description: MCU 8051 64K FLASH ISP 44TQFP
• Manufacturer: Atmel
• Series: 89LPr

Specifications of AT89LP6440-20AU

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 38
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 8K x 8
• Ram Size: 4.25K x 8
• Voltage - Supply (vcc/vdd): 2.4 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Package: 44TQFP
• Device Core: 8051
• Family Name: 89LP
• Maximum Speed: 20 MHz
• Operating Supply Voltage: 2.5|3.3 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 38
• Interface Type: 2-Wire/SPI
• On-chip Dac: 8-chx10-bit
• Number Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

16.2.2
3706A–MICRO–9/09
Using Timer 2 to Generate Baud Rates
Table 16-2.
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
is similar to the auto-reload mode, in that a rollover causes the Timer 2 registers to be reloaded
with the 16-bit value in registers RCAP2H and RCAP2L, which are preset by software. In this
case, the baud rates in Modes 1 and 3 are determined by Timer 2’s overflow rate according to
the following equation:.
Table 16-3
Table 16-3.
Mode 0: 1 MHz
Mode 2: 750K
Baud Rate
Baud Rate
62.5K
38.4K
19.2K
62.5K
19.2K
137.5
137.5
9.6K
4.8K
2.4K
1.2K
9.6K
4.8K
2.4K
1.2K
110
110
110
110
lists commonly used baud rates and how they can be obtained from Timer 2.
Commonly Used Baud Rates Generated by Timer 1 (TPS = 0000B)
Commonly Used Baud Rates Generated by Timer 2 (TPS = 0000B)
Modes 1 and 3
Baud Rate
f
f
OSC
OSC
11.059
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)
4
(MHz)
6
6
=
----- -
16
1
×
-------------------------------------------------------------------------------- -
[
CP/RL2
65536
SMOD1
0
0
0
0
0
0
0
0
0
Oscillator Frequency
0
1
1
0
1
0
0
0
0
0
0
0
AT89LP6440 - Preliminary
–
(
RCAP2H,RCAP2L
C/T2
0
0
0
0
0
0
0
0
0
C/T
X
X
0
0
0
0
0
0
0
0
0
0
TCLK or RCLK
Timer 2
1
1
1
1
1
1
1
1
1
)
Mode
]
Timer 1
×
X
X
2
2
2
2
2
2
1
1
1
1
-------------------- -
TPS
1
+
1
Reload Value
Reload Value
FFDCH
FDC0H
FEE0H
EAB8H
FFF4H
FFB8H
F2AFH
E55EH
FF70H
FEE0H
F55CH
F958H
F304H
DCH
DCH
B8H
F4H
F7H
70H
X
X
87