AT89C51RC-24AU Atmel, AT89C51RC-24AU Datasheet - Page 16
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AT89C51RC-24AU
Manufacturer Part Number
AT89C51RC-24AU
Description
MCU 8051 32K FLASH 5.5V 44-VQFP
Manufacturer
Atmel
Series
89Cr
Datasheet
1.AT89C51RC-24PU.pdf
(36 pages)
Specifications of AT89C51RC-24AU
Core Processor
8051
Core Size
8-Bit
Speed
24MHz
Connectivity
SPI, UART/USART
Peripherals
WDT
Number Of I /o
32
Program Memory Size
32KB (32K x 8)
Program Memory Type
FLASH
Ram Size
512 x 8
Voltage - Supply (vcc/vdd)
4 V ~ 5.5 V
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
44-TQFP, 44-VQFP
For Use With
AT89STK-11 - KIT STARTER FOR AT89C51RX2
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Data Converters
-
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
AT89C51RC-24AU
Manufacturer:
ATMEL
Quantity:
5 000
14. Baud Rate Generator
16
AT89C51RC
Timer 2 is selected as the baud rate generator by setting TCLK and/or RCLK in T2CON
5-2). Note that the baud rates for transmit and receive can be different if Timer 2 is used for the
receiver or transmitter and Timer 1 is used for the other function. Setting RCLK and/or TCLK
puts Timer 2 into its baud rate generator mode, as shown in
The baud rate generator mode is similar to the auto-reload mode, in that a rollover in TH2
causes the Timer 2 registers to be reloaded with the 16-bit value in registers RCAP2H and
RCAP2L, which are preset by software.
The baud rates in Modes 1 and 3 are determined by Timer 2’s overflow rate according to the fol-
lowing equation.
Figure 14-1. Timer 2 in Baud Rate Generator Mode
The Timer can be configured for either timer or counter operation. In most applications, it is con-
figured for timer operation (CP/T2 = 0). The timer operation is different for Timer 2 when it is
used as a baud rate generator. Normally, as a timer, it increments every machine cycle (at 1/12
the oscillator frequency). As a baud rate generator, however, it increments every state time (at
1/2 the oscillator frequency). The baud rate formula is given below.
where (RCAP2H, RCAP2L) is the content of RCAP2H and RCAP2L taken as a 16-bit unsigned
integer.
Timer 2 as a baud rate generator is shown in
TCLK = 1 in T2CON. Note that a rollover in TH2 does not set TF2 and will not generate an inter-
T2EX PIN
OSC
T2 PIN
÷
2
TRANSITION
DETECTOR
Mdes 1 and 3 Baud Rates
Modes 1 and 3
-------------------------------------- -
NOTE: OSC. FREQ. IS DIVIDED BY 2, NOT 12
Baud Rate
C/T2 = 0
C/T2 = 1
EXEN2
TR2
=
CONTROL
CONTROL
------------------------------------------------------------------------------------- -
32 x [65536-RCAP2H,RCAP2L)]
Oscillator Frequency
Figure
RCAP2H
TH2
=
Timer 2 Overflow Rate
----------------------------------------------------------- -
EXF2
RCAP2L
14-1. This figure is valid only if RCLK or
TL2
Figure
16
INTERRUPT
TIMER 2
÷
2
14-1.
"1"
"1"
TIMER 1 OVERFLOW
"0"
"0"
"0"
"1"
÷
SMOD1
RCLK
TCLK
÷
1920D–MICRO–6/08
16
16
CLOCK
CLOCK
Rx
Tx
(Table