Electronic Components Datasheet Search
Selected language     English  ▼


AT89S52-24PU Datasheet(PDF) 15 Page - ATMEL Corporation

Part No. AT89S52-24PU
Description  8-bit Microcontroller with 8K Bytes In-System Programmable Flash
Download  38 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  ATMEL [ATMEL Corporation]
Homepage  http://www.atmel.com
Logo 

 15 page
background image
15
1919D–MICRO–6/08
AT89S52
11. Baud Rate Generator
Timer 2 is selected as the baud rate generator by setting TCLK and/or RCLK in T2CON (Table
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 Figure 11-1.
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.
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 Figure 11-1. This figure is valid only if RCLK or
TCLK = 1 in T2CON. Note that a rollover in TH2 does not set TF2 and will not generate an inter-
rupt. Note too, that if EXEN2 is set, a 1-to-0 transition in T2EX will set EXF2 but will not cause a
reload from (RCAP2H, RCAP2L) to (TH2, TL2). Thus, when Timer 2 is in use as a baud rate
generator, T2EX can be used as an extra external interrupt.
Note that when Timer 2 is running (TR2 = 1) as a timer in the baud rate generator mode, TH2 or
TL2 should not be read from or written to. Under these conditions, the Timer is incremented
every state time, and the results of a read or write may not be accurate. The RCAP2 registers
may be read but should not be written to, because a write might overlap a reload and cause
write and/or reload errors. The timer should be turned off (clear TR2) before accessing the Timer
2 or RCAP2 registers.
Modes 1 and 3 Baud Rates
Timer 2 Overflow Rate
16
------------------------------------------------------------
=
Modes 1 and 3
Baud Rate
---------------------------------------
Oscillator Frequency
32 x [65536-RCAP2H,RCAP2L)]
--------------------------------------------------------------------------------------
=




Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38 


Datasheet Download



Related Electronics Part Number

Part NumberComponents DescriptionHtml ViewManufacturer
ATMEGA3290P8-bit Microcontroller with 32K Bytes In-System Programmable Flash 1 2 3 4 5 MoreATMEL Corporation
ATTINY25_068-bit Microcontroller with 2/4/8K Bytes In-System Programmable Flash 1 2 3 4 5 MoreATMEL Corporation
AT90S2313_028-bit Microcontroller with 2K Bytes of In-System Programmable Flash 1 2 3 4 5 MoreATMEL Corporation
ATMEGA325P_068-bit Microcontroller with 32K Bytes In-System Programmable Flash 1 2 3 4 5 MoreATMEL Corporation
ATTINY22L_18-bit Microcontroller with 2K Bytes of In-System Programmable Flash 1 2 3 4 5 MoreATMEL Corporation
ATMEGA16HVB8-bit Microcontroller with 16K/32K Bytes In-System Programmable Flash 1 2 3 4 5 MoreATMEL Corporation
ATMEGA16_068-bit Microcontroller with 16K Bytes In-System Programmable Flash 1 2 3 4 5 MoreATMEL Corporation
ATTINY261_068-bit Microcontroller with 2/4/8K Bytes In-System Programmable Flash 1 2 3 4 5 MoreATMEL Corporation
AT90S8515_018-bit Microcontroller with 8K Bytes In-System Programmable Flash 1 2 3 4 5 MoreATMEL Corporation
ATMEGA162V_078-bit Microcontroller with 16K Bytes In-System Programmable Flash 1 2 3 4 5 MoreATMEL Corporation

Link URL

Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Bookmark   |   Link Exchange   |   Manufacturer List
All Rights Reserved© Alldatasheet.com 2003 - 2017    


Mirror Sites
English : Alldatasheet.com  , Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp  |   Russian : Alldatasheetru.com
Korean : Alldatasheet.co.kr   |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com  |   Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl